I think there are probably tons of people out there who don't do any ADRs, in fact there are probably a good number of visitors who don't even know they exist. In the 90s when it was just DH and I, we never did TS. Part of it was ignorance to what was available, and part of it was we were travelling on the cheap back in those days.
Fast forward to present day and with my DS, I actually prefer to have ADRs. You could set a watch by when he's hungry, very set in his meal times, so for me, it's less stressful to have that time already booked than it is to try to find a QS at the time he's hungry (which is always peak times for him) and then battling QS lines/table hunting, etc... Because the financial part is not as big a concern to us anymore, the ADRs work well for us. I also like the break of having somewhere to sit, in the cool air during our summer trips. The last two trips, we did ADR breakfasts (all character buffets) and an ADR lunch. We left our evenings open because we never knew how long we'd last in the park, so often the supper meal was just at our resort QS. For this upcoming trip, I'm going to try ADRs for dinner as well and see how that goes.
Honestly though, if it were just me, I would probably not bother with ADRs and just eat when I was hungry and take a chance on getting a last minute ADR when I wanted one.