I think 'age' has a lot to do with people buying a 'boondocking unit' vs. an 'all electric unit' used for pole to pole use.
In my late 50's and I have no interest in boondocking as a mode of camping. Actually, I've never 'tented', etc. I'm a very late bloomer to camping but hit the ground running as I love it!
I have joined my camping group in Quartzsite BLM land for 5 days or so for couple of years and that's my extent of 'boondocking'. We like full hook-ups and resorts!
We can certainly boondock for weeks as we have a 235 gallon diesel tank and a large holding tank (165 gallons for black and grey), 165 gallons fresh tank.
I never wanted propane on board as it's so flammable. Our first coach was all electric with the Aqua Hot for heated water and furnace. One fuel worked for us then and now.
Safe travels,
MM.