I’ll accept your premise that there are good contemporary artists if you search for them.
However in the 60’s, 70’s, and 80’s you didn’t have to search.
No question. But keep in mind that the music scene in previous decades was not as fragmented as it is today. In the 1960s it was possible to know more or less all major recording artists in rock, r&b and country. Today?
Still, the best have always come out of the margins, out of the left field, I think. If not the ‘best’ then certainly the most interesting and unusual. And to hear that, you had to search. Who ever heard of Doug Sahm or Delbert & Glen in the 70s, to cite just two Texas examples?
I certainly had to search on my own in the 70s. Didn’t want disco, KISS, etc.
I started listening to the Beatles on my own as a yute because I saw Help on tee vee one Saturday afternoon. Got the soundtrack and went from there.
They weren’t on the radio in the mid-70s. Too busy playing the “New” sounds from the boys like Wings (”Somebody’s Knocking At The Door”, et al), Solo Ringo, Solo Harrison, Solo Lennon...