The Snap Store server is closed source and controlled only by Canonical. There is currently no fully functional FOSS reimplementation of the Snap Store server.
And software that releases only via Snap makes their use very limited. Before X went full Snap-only, I could at least download their .deb and easily "ar x" and "tar xvf" to get the executable which I could run, but now... nope.
I avoid Snap and any piece of software that publishes their stuff on Snap only. You cannot even download stuff from Snap, you need "snapd" running and then you gotta run "snap install X". Bah. To me it is pretty much equivalent to Google Play Store, except for desktop, and for Canonical.
Oh, and you cannot download older versions of the software.