I think you're just arguing for the sake of argument. First of all, I don't think anyone (or everyone) is saying "it's only available on CD, that's why I won't use streaming services", I, for instance, do both ripping and streaming.Hi Bill , streaming claims by some to be hi Res , therefore the ultimate source. Tell me what music you cannot find? I have very niche tastes and I am yet to encounter a problem. The same argument was used against CDs. It's only available on records so I will not buy CDs .
Of course if you are ripping remastered CDs then ....
Secondly, it seems you suspect that the "some music is not available on streaming services" argument is BS because you haven't had a problem in this regard. Let me tell you there's actually plenty of music missing from streaming services, ranging from old local music to world renown stuff like Porcupine Tree. Yes, major PT albums are completely missing from Tidal!!
Also, Tidal offerings differ from Spotify, for example. I recently discovered a band called "Big Big Train" and on Tidal you can find only their newer albums. So I was left with 2 options: listen to their older album on Spotify, in s***ty mp3, or NOT pay for 2 services and fill the gaps with CD rips or hi-res downloads.