It really is very simple. We have been on the road now in our 14th year. We workamped in many venues about 6 months a year and spent the other 6 traveling. We haven't hated it and have had many wonderful experiences. What would you trade for watching bear catching salmon amidst a setting replete with northern lights that most people can only dream of and still get paid $10/ hour plus a free site with all amenities? (we did it in AK for 5 months) Would you trade it for $5/hour? Would you trade it for nothing but site? We've done all of the above and have rarely been disappointed.
As far as a cap, no. We've worked as many as 20 hours each for nothing more than full hookups because it was where we wanted to be, when we wanted to be there and doing what we enjoyed doing. For example, we "worked" in a location in OR that required we do 30 hrs per couple for just site and FH. We were located in a private homestead where the owners were building a nature preserve on the 20 acres that they owned. Our "work" consisted of removing non-native plant life and general VERY light maintenance This all 30 miles from nowhere aside 2 streams and amid some of the most lush terrain in the country. Sometimes one can't put a price upon happy.
There are folks who will argue that to trade their time for less than what THEY believe that they are worth worth is horrid! I feel sorry for them. They still don't get that it isn't at all about material gain. They likely never will get it and are extraordinarily limited as to what they can experience.
YOU are the only one(s) who can decide the balance between what you consider "work" and what you are receiving in return, and again, that frequently isn't a matter of just a full hookup site or other amenities. If you allow it, it can mean peace, not only literally, but with your soul (whatever you perceive that to be) and truly enjoying what is left of your ever dwindling life.
It just occurred to me that I sound like an old hippie. :) Never was one but the last point is crucial. Many of us are looking at the waning years of our lives. Apropos to the discussion: how do you want to spend yours?