I know I'm a Professor Eno obsessive but perhaps him leaving after the first two albums was the tipping point.
Luckily he has made a gazillion albums as a solo artist plus collaborations with masses of people, while producing everyone else.
Currently Spinner (Eno & Jah Wobble) playing on my...
The Belew, Bruford, Fripp & Levin version of the mighty King Crimson. Could do all the 1970's classics plus the Discipline era stuff e.g.
https://www.youtube.com/watch?v=lnGD8RI0kGQ
Hawkwind similar to the Fall, so many lineups, some better than others, Space Ritual era probably the best but Spirit of the Age Tour 1977 was almost as good.
Not having that about Fleetwood Mac, they might as well have been a different band when the Yanks arrived. Peter Green was irreplaceable.