Because more and more things are only packaged as snaps.

Only Firefox is shipped as snap on default install.

But Firefox packaged by Ubuntu was always gimped as they didn't enable certain optimizations like PGO/LTO so official tar.gz from Mozilla was superior anyway. (They fixed this recently for snap). I think it's similar for Chromium.

So I didn't use snaps and I never been in situation that I needed to use snap.

Firefox isn't the only thing that has been switched off .deb and to a snap. LXD, for example, has been shipping as a only a snap for years.

But even if it were only firefox, telling people they should download tarballs instead of having their distro ship packages is really missing the point.

The problem is when you instruct a colleague to check something using nmap, they install nmap using snap and are surprised it doesn't work, while you are left wondering what the hell is wrong with their computer, oblivious to the footgun Canonical put into their distro; until you remember again after a decade+ of not using Ubuntu. Canonical shouldn't push out broken things like that. It's supposed to be a distro where stuff Just Works(TM).