We do not use snap for anything, but Ubuntu has begun to package a number of things as snaps wrapped in debs (so it may be that some of the packages that get pulled in during install of Virtualmin or just as part of the base OS provided by your hosting provider, are snaps bundled into deb packages). You probably cannot remove snap safely. Take it up with the Ubuntu folks, it has nothing to do with us.
As someone who uses Ubuntu for all their servers, I’ve never found “snapd” as being necessary. I’ve safely removed it from a number of servers without it ever affecting the system or Virtualmin in anyway.
Typically Ubuntu comes installed with:
core20
lxd
snapd
lxd - is a system container and virtual machine manager. you only need this if you know what it is, and are actively using it. most are not.
core20 - is a snap that offers dependencies for installing other snaps. not using snaps, you don’t need it.
snapd - is the snap daemon. not using snaps, you can safely remove it.
To get a list of “snaps” run:
snap list
If you notice any snaps not mentioned above, investigate what they are before removing them and/or the others.
Feel free to consult with me, if you have questions regarding your installation. As @Joe has already mentioned Virtualmin itself does not reply on snaps.