Oh - really ?
What you said regarding commercial recordings is probably true - they may well be even poorer than that.
Other is debatable. It is true that cartridges capable of full amplitude response to 20 kHz under RIAA are few - but they do - or better said - did - exist. When you combine the best recordings and play them back with this calibre of cartridges that do not go berserk even at full gas all the way to 20 kHz, this is entirely different game than CD.
It can not even be compared...
Most of these cartridges are also capable of "essentially flat" response to and beyond 50 kHz - test records that go to 50 kHz without the RIAA preemphasis ( all test records are made that way ). This "falling at 6 dB/octave/-20 dB by 20 kHz" mimics really well the maximum amplitude/frequency of the sound in music - when actually called upon to play > 20 kHz, such a great cartridge would have no trouble whatsoever.
Essentially, you and me differ in one thing regarding the vinyl; you represent the (lazy?) pro "bussiness as usual" approach ( citing each and every possibility why it can't be done ) - whereas I am trying to find each and every way how it could be done - IF and WHEN people are willing and able to go an extra mile.
Most definitely possible with vinyl - and proven many times over.
P.S: I think we two could, TOGETHER, bring vinyl much forward.