There are lots of old motorhomes still fully functional out there. I see questions about them all the time on these forums. Someone must be keeping them on the road, and liveable. The owners range from weekend warriors to full timers, as far as I can tell from their postings.
Many repair shops have facilities you can use while your rig is serviced. If not, there's always a motel/hotel near a repair shop. Easily affordable with all the money saved by not owning both a motorhome, and a bricks and sticks?
Always with the negative waves, Moriarty, always with the negative waves?
Some RVs depreciate faster than others, but that's life. Don't dwell on it. You'll just lose more sleep.
Did you "fail to plan" those times when your trips were interrupted? Not much you can do about some types of problems when traveling. You either learn to adapt and roll with the punches, or stay home.
Full timers have their challenges, but they do it for the rewards, like freedom, endless curiosity, new places, new faces, new experiences.
Each to his own?