I agree this is really annoying and feels like something that could be semi-automated ie. “This track is no longer available on Qobuz, do you want to replace it with one of these versions?” — either individual or en-mass.
Roon is meant to be my central music manager, but if I can’t easily manage my playlists sensible/easily (and tracks are silently falling off them) then it’s failing heavily in that regard as a one-stop solution.
But short of the above, even a nicer means to manually replace a track in a playlist would be a good start.