>>127650436 (OP)
I had the exact same opinion as you when I had only ever heard the stereo mix. Once I got the mono version, it became abundantly clear that it is their best work.
Itβs not even so much that the mono mix is so great as it is the stereo mix is so bad. First 30 seconds of Taxman are a perfect example. All the instruments and half the vocals are in the left channel while the right channel is empty save for half the vocals and the occasional tambourine/cowbell. The hard panning is bad enough without the terrible balance on top of it. A lot of the double-tracked vocals on several songs from the mono mix are either absent on the stereo mix or are split between the two channels so they lose the effect.
Rubber Soul, Revolver, and Sgt. Pepper are the 3 Beatles albums that need to be heard in mono instead of stereo.