So a few popular Linux distros decided to drop a few major packages like how red hat dropped rpm packages for libreoffice in favor for the flatpak packages.
If more distros decided to drop more packages from their main repository in favor for flatpak packages, then are there any obvious concerns? From my personal experience, flatpaks didn't work well for me. If flatpaks become mainstream and takeover the linux distros, then I might just move to Freebsd. I just want to know if there is any positives to moving away from official repositories to universal repositories.
I'd say it's the future but it's kind of already the norm. They're just a lot better then system packages in a lot of ways. Predictable, one system developers have to target, portable, immutable, and system agnostic. Linux has needed this for a long time. This is similar to how apps on your phones work. Windows is going this route too, and I think OSX does it too but I don't use that garbage os to know.
MacOS is similar but better. The sandboxing and permissions were planned and implemented long ago, and getting a new app is as simple as downloading its .app bundle and running it.