my current guess is: this problem will mostly fix itself
youtube-ads are ridiculous. I wouldn't consume these as they are now. If I'm forced to use that site without sponsorblock and adblock, I'm tending to just never watching anything there.
So if NewPipe/Sponsorblock (and of course NewPipe+Sponsorblock) are gone, then I won't use that shit anymore and don't feel any pain.
Same as with reddit. The last weeks I visited when pointed to reddit by some search enigne, but not out of "I could browse it for fun". I didn't miss anything. Twitter? Not even trying to visit that shithole anymore, since most links are unreadable anyways.
If platforms are closing down, they will lose my interactions. More free time for me!
I don't get what your point is.
Should flathub remove the warning or proprietory software?
And why do you think snapstore would be any better in that regard?