The Beatles early stereo mixes sound awful. They are truly great examples of a mix engineer/producer growing up in public with regard to the relatively new fangled stereo for pop.
As Ethan says - the bass guitar may appear to be to a side but that's the higher frequencies that cue position in a stereo or multi image.
If it were the full bass guitar freq range (without a n HPF or a split) the stylus & cartridge would dance all over the place.
I've been listening to a lot of CD, FLAC etc with h/phones lately and the ones that haven't the kick drum and bass guitar centred give me listening fatigue very quickly let alone bothering the hell out of my preconceptions