What is turntable “liveliness”.

.05% of 33.33 rpm is 0.01666 rpm. I doubt any turntable one can buy is accurate within +/-.01666 rpm, but I do agree that absolute speed accuracy is overrated.  Rather, speed constancy is what differentiates among turntables, the capacity to hold speed constant despite stylus drag and groove tortuosity (which of course does add to stylus drag). This is one of many reasons why turntables sound different from one another, and it's folly to think otherwise.

But it seems you’re saying that one required a good acoustic, by which I assume you mean a good listening room, to divine the difference between early RBCDs and vinyl. In my opinion there’s no listening space bad enough to obscure the vast gulf between them. Classical music was most mutilated on RBCD, as opposed to other genres. Massed brass or string passages sounding like the crumpling of cellophane.

Mahgister, if you preferred early RBCDs to vinyl as it was ca mid-1980s, then just to begin with, we are miles apart. I found early RBCDs to be so odious that I could not stand to hear them even in someone else’s house, let alone in mine.

Ossicle, Like I and someone else said, you have a lot to learn about turntables. This is not to say that I think you have to spend $50K to hear differences among turntables, or even $25K, or even $10K. Anyway, your position is weakening; you just wrote "almost any decent turntable". That implies you concede that some decent turntables sound different from other decent turntables. Finally, of course there is something "wrong" when you can "hear" a TT. That’s the point.

“Turntables have no sound” is the theoretical goal. But real world turntables don’t get there.

It's impossible to "prove" either side of this debate, because there is a subjective element that cannot be removed from the equation, although I don't know that intrinsic SQ differences among turntables (excluding the obvious differences among tonearm/cartridge pairings) that I and others hear could not be measured, if one knew what to measure.  As things stand, we can agree to disagree.

In Pindac, TA means ToneArm

That is for you to find out after you have compared a variety of TTs in your home system.  Speaking for myself, if you don't already "believe", it would be a waste of time to convince you, but I do think that your own experience will eventually teach you.  The trick is that you need to compare two like turntables (drive system, speed constancy, etc), perhaps two identical turntables, mounted differently from each other, in order to get the point.  So, a Linn LP12 is not a good starting point, because it is quirky in so many possible ways other than what we want to focus on.

Disagree. Turntables make a big difference, but never to the exclusion of the effects of the tonearm/cartridge match. My listening experience suggests that the tonearm and cartridge should be considered as one. As a result, within limits of course, you cannot say this tonearm is better than that tonearm (if both are of high quality) without also stipulating the cartridge. Likewise, where two cartridges of similar excellence are concerned, a comparison is not believable unless they were auditioned in the same tonearm. On that background, the turntable has many additional important effects. The timekeeping function, just to begin with, should not be trivialized, because less accurate turntables are adding colorations due to their speed instability. In addition, the shape of the plinth itself and its build materials and its isolation from environmental perturbations have a significant effect on every aspect of the listening experience.