It was really something to learn that all those classic songs from the 60’s weren’t even played by the groups that supposedly played them.
Yup.
I know exactly how you feel. Have you ever watched the documentary about "The Wrecking Crew" directed by Denny Tedesco? Denny is the son of Tommy Tedesco, the noted studio guitarist who played in The Wrecking Crew.
The documentary is a real eye-opener. I remember seeing a number of top acts in the late 60s and early 70s whose studio work was done by The Wrecking Crew. I don't think I was more let down than when I learned that TWC did a lot of work for The Beach Boys. I was on the concert committee at the University of Missouri 1969-1971 and we brought in The Beach Boys and, at the time, I believed they did all of their own work. I didn't realize at the time how much work went into studio production work. It was hard for live acts to make their sound somewhat similar to what was recorded in the studio.