Huh. I'm sure there's some projects that release exclusively via docker or snap/flatpak, but in my experience that's pretty uncommon. Far more often I see a release page with a dozen or more options. Binaries for Arm, AMD64, flatpak, snap, a few flavors of Mac, dockerfile, and of course the venerable tarball. The advanced will have deb and rpm as well. I see these options as very much aligning with the spirit of free or open source software: everyone can pick what's best for themselves.

Obviously when the choices are removed and there's cramming down throats, that's a problem. And I'm sure being forced to shuck software from a container would leave a bad taste. However I don't see the popularity of the formats you dislike as causing a broad decline of those you do.

It's becoming more and more common in my experience, hence the long post. Ubuntu's notorious hiding snaps in apt by writing wrappers and making it hard to work around it is the next level of this trend - and it is deplorable. That type of obfuscation and attempted deception is not the spirit of open source.