It's annoying fragmentation when even for a stable distributable package there's flatpak as a standard, and I've never seen why Ubuntu needs their own with a proprietary store.
Like I generally tend to favor native packages, but I can at least appreciate Flatpaks having advantages and times even I want to use them. (Largely when stuff is a pain to compile on Arch for library reasons.) Snap is a non-universal universal package format.
(Also going to shout out AppImages, which are an entire package as a single ELF file you can run on basically any distro. I'm not sure how good they are for important work, but I just think they're neat and have come in handy for running stuff on old CentOS in the past.)