Found it hard, when I first started listening to jazz in the late 70s, with music before about 1950. Part of this was that restoration techniques were not what they became in the 80s and there were a lot of dubious things on sale with no real effort. I had a Charlie Parker/Miles Davis LP that put me off trying Parker for another ten years.
Restoration does miracles nowadays and I've generally acclimatised to the sound of earlier years - you just adjust within a few minutes of listening.
But to untutored ears I know it can sound totally off-putting. You need to have motives to persevere.