Over the last 25 years I've owned five different trucks and five different 5th wheels.
Only the most recent truck was a 4WD, but with all truck/trailer combinations I have camped in one of the most difficult areas, a farmers field (a club we belong to frequently rents fields). I've never been stuck.
No 4WD is probably not a requirement for most people, but it is certainly nice to have. I usually go into 4-Hi to leave the yard (it's a bit steep) and often into 4-Hi in the field. I did go into 4-Lo last year to pull someone else that had gotten their 4wd truck/trailer stuck (an F450)