Sadly what you say has been true. I have been lucky, and really always had pretty decent playback equipment. In the mono era, I built my own mc cartridges, and tacked at 3 GM before anyone else. My nylon cord stylus suspension was shared with and adopted by Decca, for the ffss. Those not mc, but moving iron variable reluctance, but they did not and do not use a cantilever.
Early Decca ffss 78 rpm mono head.
Certainly the LP is capable well below 40 Hz, but some cutting lathes has low frequency rumble, so a high pass filter at 30 Hz can make sense.
I used mainly European pressings, in the early days, us pressing were markedly inferior in many ways. I think also in that "Golden age of British Audio" play back systems over there were superior to the US.
The real issue though with the LP and part of this was microphones of the time, was HF distortion.
Peter Walker's Quad preamps always had the great secret weapon of filters with 10K, 7k and 5K turnover frequencies with a continuously variable slope. This was just brilliant. Harold J Leake copied it with his Varislope, but it was not as useful as the Quad.
This is so effective, that I believe if you have a large legacy collection of LPs, a Quad preamp is part of the basics.
That is the reason for this.