I was being encouraged to learn programming by my brother-in-law, so when I was going through the lessons in the course he bought there was a section on Linux. At first I was thinking on how would I be able to install in a virtual machine but my brother-in-law in all his wisdom said “why don’t you dual-boot”. After some planning so I don’t nuke my hard drive and flashing LMDE as my first distro I installed Linux and did the rest of the course there.
I think there would be a way to test it with docker, you could find a image that has systemd installed and use something like distrobox to test it with the GUI.
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.
If you are using Ubuntu and disabling snaps, might as well use something else. Snaps are basically the selling point of Ubuntu and any other distro based on it will provide a better experience if you don’t want them.