Pure opinion: for the most part, high end frames are made/assembled by humans, which means that each one is somewhat different. For example, have owned more than a dozen Merckx frames and only two of them really ‘spoke’ to me. Kept one and really regret selling the other. Same deal with other brands and models, just bought & sold one after the other until coming upon the right one that had a great ride for ME…which may not have the same ride qualities for YOU.

Truly mass produced frames are more consistent. For example, have owned at least a dozen 87 Schwinn Tempo’s over the years and each one has been very, very good. Good enought that someone always came along and offered to buy the one I had, and good enough that eventually I’d buy another one. Not high end, Columbus seamed tubing, but they just work really well. So, there’s that.