The reason is probably the capacitance loading.
All cartridges require a different capacitance loading. The problem is that the capacitance loading of cables and preamps vary widely. This has nothing to do with how they correct the RIAA curve which is nearly always correct in my experience.
The correct loading for every cartridge is unique.
In the past this has been handled by some.
For instance my SME arms have low capacitance cables. Back in the day SME assumed owners were competent and so you soldered the correct capacitor to the terminals on the base of the arm. So this is what I do with my SME arms except one
Peter Walker of Quad put dip switches on this Quad 44 preamp, so you could set the correct voltage gain for your cartridge.
Also have a vintage Decca ffss arm and head, and its preamp is a Quad 22 I have had for around sixty years. Now Peter found that the Decca ffss heads worked best with a load impedance of 68K ohms rather than the standard 47K. At that time in the UK Decca ffss heads were by far the commonest and pretty much universal on high end turntables.
One of the problems with disc reproduction is that really the only standard is RIAA curve and 47K ohm input impedance for moving magnet and variable reluctance cartridges, with moving coils being a very different ball game.
So the difference you are hearing, if indeed there is a true difference is due to differences in loading capacitance of the wiring from cartridge to preamp and the capacitance loading of the RIAA input most likely.
Optimizing disc reproduction is not straightforward because of a degree of lack of standardization, which due to different cartridge designs is virtually impossible.
Vintage Decca/Garrard Quad 22 rig.
Same turntable with 78 Decca head. They slide on and off.
I seem to have accumulated a number of turntable over the years, that have had a variety of SME arms at one time or another.
This Thorens TD 150 I bought in 1965 it was one of the first made. It has a very low serial number. It has an SME III arm now with Shure V15 xmr. Pre amp is Quad 44.
I bought this Thorens TD 125 MK 11 non working and restored it for our family room and found and SME 3 arm for it. Preamp is Quad 34.
I have bought very few LPs since the CD really came of age. But I have a large legacy collection going back to when I was seven years old and that was the mono era.
LP reproduction can be very good, but everything has to be just right from turntable, arm, wiring and correct input loading, that includes input capacitance seen at the cartridge and correct loading impedance. The latter is pretty much standard at 47K and correct playback of the RIAA curve. In my experience the big variable is the capacitance as seen at the cartridge terminals.