Back in the day, effects weren't as common as they are nowadays, but I don't believe that popular recording artists shied away from them. They didn't have as many choices and opportunities to be as OCD as we do nowadays. They used what was available and embraced new sounds and new technologies. Like us, they listened, learned, and used what sounded best to them. Mark Farner's fuzz in GFR's early albums sounds er... "funky", Maybe he really liked it but it's a tone that few would want to emulate nowadays! Quicksilver's "Happy Trails" had some amazing tracks although they were largely stitched together in the studio from the best parts of their live recordings (some of their live performances really stank, LOL!). No one does whammy bar like John Cippolina did. Hard to say about James Gang, but Joe Walsh seemed to like to use effects in the studio like Echoplex, Leslie speakers, multitrack, and backwards guitar. For better or worse, none of 'em had a Line 6 Helix back then.