I do agree that OW F lounges are far superior but I find I rarely get the opportunity to use them as most of my travel originates in regional UK or EU cities where they don't exist. I certainly wouldn't route my travel through LHR from those just to use one. The AA FL lounges are a nice benefit but they're nothing special and, again, few and far between.

That said, if I was SE England based or was a regular user of locations where there was an F lounge my view would probably be different.