I‘m not interested in what the most music on tidal is. What I know is that many MQA titles I‘m listening to (not very old classical records, pretty recent vocal jazz records) are for sure not taken from old analog tapes

With this kind of reasoning, there is no point in hi-res altogether...
And for sure technically those records in MQA are better than just redbook. It‘s not only because of the resolution. To a large part it is due to a filtering issues, as with those MQA encoded records the cut-off frequency moves from 22kHz (where some audible artifacts can be perceived) to 48kHz, where possible artifacts would bother no one, but bats, e.g. I don't care about 3dB loss at 47kHz that might occur due to usage of a slow roll-off filter....