The webserver that canonical uses to distribute other people’s snaps is, and that’s it. APKs aren’t proprietary just because Google runs the Play store.
If you don’t want to interact with canonical’s servers you can download the snap files from literally anywhere else and install them manually so you don’t have to touch a single line of non open source code.
Even if you do download the snaps from elsewhere you are still locked in with the Canonical repository for updates, with it being basically hard coded and with no alternatives. Even more, snaps are straight up a worst experience then flatpak with all their quirks like the loopback devices and the automatic updates.
Disable automatic updates then. snap --help
IMO snaps were prematurely pushed but that’s about it - they were a worse experience like two years ago when canonical started pushing them and almost every app had some quirk due to the sandboxing, but they have improved to the point that I literally can’t remember the last time I encountered an issue with the snap version of a program (granted I only really use snaps when something isn’t available as a .deb or there is a conflict)
