From the “universal package formats” that’s the one I’ve had issues with when using it on a distro not specifically mentioned to work, it was supposed to be universal! Though not sure if that’s an issue with whoever packaged the app or anything specific with AppImage. Poor experience anyway.
Also no repo model. I like package manager to deal with shit. We have sorta solutions for that but not quite like snaps and flatpaks.
Also the dependencies stuff is weird. They advice you to think of the oldest (LTS?) distro you think the app will be used on and use deps compatible with that one. Which just seems, I dunno, icky, for lack of better word.
But for a random one-off app, I think it’s fine. I prefer flatpak but it’s fine, I wouldn’t avoid it or anything.