sdrsdrsdr,
"But I have to say piano from some of these tapes was the closest to the piano downstairs that I’ve ever heard in my room. But not in the audiophile sense. The tapes don’t have the frequency extension, soundstage, and air. But wait. Neither does my piano."
It's always more interesting to hear about direct comparisons rather than what we audiophiles think or expect that we should be hearing.
I'm not too surprised that tape came out ahead in your experience here despite expectations of 'frequency extension, soundstage, and air.' This kind of unexpected result, which has happened to me on a few occasions, can take a while to fully sink in.
Regarding MM v MC cartridges, I favour the former as they have a higher output and are less fussy regarding arms and might even track better. Sound archivists and broadcasters also tend to stick with Moving Magnets.
It's also worth bearing in mind that the cartridge is in effect little more than a slave electrical generator under total control of a much larger and important one - the turntable drive motor itself.
Anything the motor (turntable/arm) does incorrectly will be inevitably magnified by the cartridge output, even moreso for MC cartridges which unfortunately have a lower output etc.
Just where the bottleneck with today's vinyl playback systems is will depend upon which turntable, which arm, and which cartridge. Case by case.
Cost can be a very poor indicator of performance for all three components. Nothing new here.