Is this installing a local .deb file or installing from a repo? If installing from a repo, the .deb and the full file path are unnecessary. If you’re installing a downloaded file, use dpkg -i package.deb not apt.

The barrier for me is that I use a lot of apps which require native messaging for inter-program communication (keepass browser, citation managers talking to Libreoffice, etc.), and the portal hasn’t been implemented yet. Its been stuck in PR comment hell for years. Looks like its getting close, but flatpak-only is a hard no go for me until then.

Even after that, I would worry about doing some Dev work on atomic distros, and I worry about running into other hard barriers in the future.