But, Ovi, popular music/youth culture peaked in the 60s (fact) and thank the Lord that The Beatles weren't still around in 1975 or 1985 to make their version of 'Black and Blue' or 'Dirty Work'.
A 12 inch disco remix of a new 1978 Beatles' single anyone?
All the stuff you mention is just the padding, the stuff after the Lord Mayor's Show, made by people who'd either done better things in the 60s (Lou Reed, The Who, The Beach Boys, Paul) or by people who didn't do things as good as that from the 60s (Roxy Music, New York Dolls, Black Sabbath)!
Padding with increasing poor graphic design, quality of the actual vinyl (check out 60s vinyl compared to stuff released by, say, Wings), clothing, drugs, well.....just about everything.
It also represents, categorically, a far less interesting and exciting time to live in than the 60s.
Of course, other opinions are available!
Anyway, back to the story, you'll be pleased to know that I 'DO' own a record from 1973.....sort of.
In the 1990s Trunk Records put out a soundtrack LP for the 1973 film 'The Wicker Man'.
1973: 'The Wicker Man' soundtrack.