We just returned from a fifth family trip to Disney World. Three of those trips were spent at Disney World Resort value hotels and two were off property. Often times people will refer to staying on property as being in the "Disney World Bubble," especially if you are flying in and not renting a car.
If you are wondering which you should choose, there are pros and cons to each.
In the Bubble Pros:
No one does real world escapism better than Disney and the best way to forget that the rest of the world exists is to stay onsite. You get benefits like transportation from the airport to your resort. Your MagicBand is your room key. You can self check in, usually. There are transportation options to get to any park you want, though most value resorts are limited to bus service. This is the best way to live and breathe Disney while forgetting that anything else exists. I mean, your bus will pass a gas station and a large under construction McDonalds, but you land at your destination park ready to be immersed into the experience right away.
In the Bubble Cons:
If you want better transportation options, like boats, monorail, Skyliner gondolas, etc., you will pay a premium. That is also the case for lodging which is within walking distance of a park. For example, during a slower part of the year, Value resorts can be around $100/night and Deluxe resorts can be as cheap as about $350/night or even less, or around $700/night for the most expensive properties.
If you don't pony up for a nicer place, you will be waiting for a bus, which should be running pretty frequently, at least every 20 minutes or so, but may be running late, will usually be crowded, and you may be standing on the way. At the parks on the way back, you may be waiting in a very long line to take a bus back to your Value property, since they have a ton of rooms and are very popular. You may be waiting a while for multiple buses to take you back.
So, if you are in the Bubble, you do lose some freedom to go where you want to go when you want to go, which also means that when you need to eat you are paying Disney to survive. Even Value properties have a pretty good selection now of grocery items, think large bottles of soda, large bags of chips, cookies, bananas, milk, bread, peanut butter, things you have have in your room without too much trouble to make snacks, and the prices are only about double what you would pay at a gas station.
Out of the Bubble Pros:
Freedom to go where you want when you want is the biggest pro, outside of cost savings. On the trips where I had a car and we were not staying on property, I could visit the Character Warehouses in Orlando outlet malls to get discounted Walt Disney World merch. Is it as cheap as shopdisney.com, NO!, but you do get it right away, get the pleasure of standing in a long line just like in Disney World, and there are things you can't get online as well. Waffle House was another big pro to staying offsite. Also, Target for in room groceries meant we could get our familiar favorites.
Now, you can always take an Uber/Lyft to where ever you want as well, but that can be pricey since things in Orlando, while not super far apart, adds up. For example, a Lyft from an All-Stars Value resort to Hollywood Studios was $11 before tip, and that's just within Disney World. There is also nothing that says you can't rent a car and stay on property, but you will pay $15/night for parking at a Value resort.
It is less expensive and there are a lot of options. Disney World has a lot of options, from camping to motel style rooms to animal resort experiences to getting as fancy as you'd like, but if your budget doesn't support even $100/night, or you are booking last minute and there just isn't availability or prices are insane, like $1,700/night for Art of Animation, which is a Value resort, you will need to look at the many options just outside of Disney World. With certain partner hotels, you can even get benefits, like the ability to book FastPass+ selections up to 60 days in advance. That same week Art of Animation was $1,700/night, I was able to book a stay at a property which is a timeshare property and did that once before as well.
Timeshare properties usually have a lot of available rooms, since they may not have sold all of the contracts available, people stay at other properties within the network or just don't vacation and instead pay annual dues and waste their investment. What this means, is that a property management company has a lot of costs covered to maintain the property, including a lot of staff and a lot of empty rooms. Our stay was $55/night, and a $20/night resort fee, but since it was a timeshare owner type property, things like housekeeping was only done on request, but we did have a large one bedroom condo with pull out bed in the living room as well as a full kitchen and in room laundry. There can be timeshare sales pitches at check in, but you can just say, "no thanks."
Out of the Bubble Cons:
Parking can suck. Currently it is $25/day, but if you park hop, you only pay that once, even if you switch parks. Parking can suck if you want to do some after park hours resort hopping, as things like the monorail don't run after an hour after park close. If your car as at the Ticket and Transportation Center, but you wanted to go to Trader Sam's, but changed your mind and the monorail stopped, you may be shuffling all the way from the Polynesian across one of the largest parking lots in the world, since the helpful trams will also have stopped. If you were onsite, you may still have trouble getting between resorts late in the evening too, but you would know you need to take an Uber/Lyft.
It is decidedly less magical. I mean, the food scene is getting a lot better around Orlando, but much of it is still chains. Many chain restaurants started in Florida and you will see them everywhere, as well as bad places catering to broke tourists. Say what you want about how expensive Disney food is, but it is often creative and of good quality. Epcot festivals are a way to get unique smaller dishes for $5-$8 and sometimes that can be enough for a meal.
That doesn't even touch doing something like using a dining plan, which would be its own magic. If you have paid for your tickets, your dining plan and resort deposit in advance, there is magic in not having financial transactions for food as you wander around parks and resorts. each time you open your wallet to pay for something, a little magic flies away.
You also miss out on Disney theming at a resort if you stay off property. To save money, or sanity, people will often have resort only days, where they don't visit a park at all. This can be used to go swimming at the pool or just relax your tired feet or get away from the crowds that drive you up a wall. You can even pony up for character dining at a resort on property instead of visiting a park, so you still get photos you may want, but you'll never get that off property.
Should you stay on property or off? I think it can depend on the type of vacation you are looking for, how much freedom do you want to have with travel, if you want to do things like visit Cocoa Beach or Kennedy Space Center on your trip, or, gasp, that OTHER park, you can usually do more for less money out of the bubble.
Our last trip was 11 days and it only made sense to have a trip that long by staying off property, even if there weren't crazy rates at Disney World properties. Staying offsite means we can stay longer, which was more important than the magic feeling of being in the bubble. I'd say if you want a short trip, like 3 or 4 days, a Disney resort can be a good option for concentrated dopamine hits of happy magic juice, or heck, stay longer if you have the money, but if you have a limited budget and you want to spend a less hectic time at parks, because you will be back to each a couple of times, it may make a lot of sense to pay to rent a car on top of the offsite hotel. I mean, off site hotels often do have shuttles, but usually only have one pick up time in the morning and will have limited return trips in the afternoon and evening, so be aware of that if that is your plan.