I would rather have a snap than building from source or use some tar.gz archive with a sketchy install script
I agree, but that sounds like false dichotomy to me because snap competes with flatpak.
There are plenty of use cases that snap provides that flatpak doesn’t - they only compete in a subset of snap’s functionality. For example, flatpak does not (and is not designed to) provide a way to use it to distribute kernels or system services.
I don’t think that the distribution of system packages is the issue. People need a way to easily distribute and obtain everyday applications, and to keep them up to date in the same manner. Linus spoke about this: https://www.youtube.com/watch?v=Pzl1B7nB9Kc