For me, Snaps are the thing. Ubuntu has chosen to use Snaps even for things readily available on other distros / in many repos without the need for Snap.

Linux is about choice, and making that kind of decision eliminates some choice. And given that Ubuntu is commonly recommended for new users -- partly because it is often one of the few distros with official support for stuff -- it's extra annoying.

Edit: in practice, there are many Ubuntu-like distros that are probably just as good for new users and don't need the Snaps (e.g. Mint). But new users won't know this. If Ubuntu were not the behemoth it is in terms of name recognition, many people would care less.