This really becomes a personal preference. We wouldn't stay onsite if it was free. It just wouldn't suit our lifestyle. We're a family of 5, no way would we want to share a hotel room. Also, no way on earth am I relying on WDW buses. No thanks, not a chance. But we (I) like to drive, it doesn't bother me one bit. We also get to go where we want, when we want, instead of being limited to WDW options. Driving is super easy, IMO. MK takes a little extra time, due to having to use the ferry or monorail, but to us that's a magical part of the journey. Beyond that, park, take the tram and you're there. Easy peasy.
Many people talk about the "Disney bubble" and I get it. But to me, that's silly, the "bubble" is what you make of it. To us, the "bubble" is all of WDW and the umpteen billion things around it...gift shops, restaurants, beaches, etc... We also pack all of our food and bring it in, so having a kitchen is a must (we really do very minimal cleaning/cooking, very easy stuff).
We rent offsite condos. You can find 3 or 4 bedroom, 2 to 3 bathroom condos/townhouses for about $100/night.
Again, you'll have to decide if you want to stay onsite or not. For many, it's stay onsite or don't go. I understand and respect that. We're the opposite. In fact, our last trip, we thought we'd surprise the kids and book one night at the Dophin onsite, just for fun. We didn't even sleep there, we left and went back to our condo. Definitely not for us.