The last two courses I have been members at are definitely not at their best today.
Shawnee CC in Topeka, where I was a member for 20 years, was clearly better some time shortly after WWII. I have aerial photos from back then, and the loss of the green surface, as well as the encroachment of trees is so dramatic as to make me sad.
I'd say several of the greens are around half as many square feet as they were back then, and some rectangular greens are now round.
Fairway width dropped from 50+ yards to less than 25 in some cases. We haven't been members for several years, but shortly before we moved, the club went broke (over a 1988 clubhouse rebuild) and the new owners aren't particularly interested in it's Donald Ross roots, not that the club was much better.
Where we are now, the course was built in the late 80s with bent greens in Mesa, which probably wasn't a great idea, but converting to bermudagrass greens that don't hold as well didn't help it much. I played it a fair number of times in the early 90s when my brother was a member so I have some recollection of those days.
It, too, has had lots of volunteer trees added over the years, and there are quite a few places where I am pretty sure rough lines have been moved in. Plus, lack of $$ means the 40-y.o. irrigation system is a big problem for several reasons.
Nevertheless, both courses are still among my favorite places to play.