High item quantity + quality maps=bogus returns

I think the biggest disconnect is the number of maps run and the odds of finding higher maps. Newer players are surprised when they can't sustain maps. People playing since OB will run out of 77-78 and drop down to 75-76 or go buy maps without giving it a second thought. There really is no grand secret to sustaining maps. Just lots of little things that help push the odds more in your favor.

Rolling maps is a long-term strategy. You only really get to see the results in you record them over 100 maps or so. You won't see the results just running a high quantity map one time, then a low quantity the next.

Rolling maps and not getting anything is frustrating for sure, but after a while you just expect it and plod along until you get a higher level map pool.