Even if it's an equal price point, as tiggerdad says the "get away" factor is by far the more attractive option.
P.S. - Thanks to Bama Ed for the 2021 Rack rates analysis.
You are certainly welcome, Stork.
I often hear the complaint of campsite rates versus Value rates but remember: the Fort has tiers in location/features as do the hotels on property. Are you comparing a Preferred campsite to a parking lot view? Are the seasons comparable?
I spent a WDW stay at Caribbean Beach Resort in 2018 (hey, Cast Member discount) and didn't enjoy it as much as I hoped I would. On park days we're mostly (wait for it) in the parks. On non-park days, I was searching out the little courtyards and outside tables/chairs at CBR to DIS online, read, or stream some video. To me THAT's the area where the Fort wins hands down.
To talk to the OP, some folks may do this. A number of folks come to FW for a month or longer (on back-to-back reservations). The part of your plan that will require elbow grease is getting out in front and booking those long stays well in advance. Central Florida year-round trying to lock down 2-3 month long stays (or longer if relocating to other campgrounds) requires quick early action.
You're in Indiana. You mention possibly moving closer to Orlando and buying a trailer. Is FW the primary/only place you want to use the trailer in? Are there other places you want to visit/explore? We have some folks who live in their home spots and keep their trailer stored in Orlando and pay some one to tow it and set it up for them (or you could do that yourself) for a long stay at the Fort (or elsewhere). That means they camp around Orlando which works if that's your plan.
But do you want to camp up in Michigan? Maine? Nantucket? Tetons? If it's a Fort/Orlando area only idea, get a timeshare/condo cheap instead. I will tell you that Florida State Parks are limited to 14-day stays. You can try to book back to back there but YMMV. Some of the county places also have minimum stays.
Thousand Trails is part of a big rv/timeshare like network. Encore is another one. RVontheGo is a third (and they might be related). TT has a location in Clermont (30 min from WDW) that is timeshare like for trailer/rv.
https://thousandtrails.com/florida/orlando-rv-resort/. Tropical Palms and Lake Magic on opposite ends of Kissimmee are locations also outside WDW (so that's three long term options). Or you can slug it out getting a long stay at a KOA or a State Park.
So where do you want to use your trailer and for how long/often? Is it really JUST the WDW area?
Bama Ed