I buy a fair few vintage LPs, mostly Quadraphonic from the 1970s, mostly classical and consequently now some 50 years old and with lots of quiet bits.
I've been pleasantly surprised at how quiet many of these are, especially HMV and CBS even though at the time, those were maligned as being poor pressings compared with, say, Deutsche Grammophon. Nevertheless, once cleaned, they often play silently, with barely one or two clicks per side. Possibly those LPs, being the label's 'premium' offering were treated better, and possibly also played much less than Pop/Rock LPs.
I've also been surprised at finding a number of these LPs which looked unused, both sleeve and LP looking brand new. Possibly a warehouse find?
On the other hand, I have a fair few LPs from the same era which are unplayable due to wear, so much depends on the treatment the LPs have had throughout their life.
One further thing, I was given a box of LPs that had been flood damaged. The sleeves were all rotten, and some of the LPs were badly stained. However, once cleaned, which took several goes on the RCM, all have become playable, albeit none could be called pristine.
In other words, to sum up a longish post, LP pressings depend hugely on both the original pressing quality and how they have been treated throughout their life.
S.