> All it takes to get rid of snaps forever is `sudo apt purge snapd`.
That's not enough. Some package could eventually drag it back in.
$ apt show firefox
Package: firefox
...
Pre-Depends: debconf, snapd
If you really want to keep it off your system for good, you need something like this:
$ cat /etc/apt/preferences.d/no-snapd
Package: snapd
Pin: release a=*
Pin-Priority: -1
$
