that is the question. Snap is a software packaging and deployment system developed by Canonical for Ubuntu, allowing applications to be distributed in a self-contained format that can work across various Linux distributions. Because Flatpak and AppImage already existed and have more or less the same goals it was probably a Not Invented Here move. And although it is available for other Linux distributions you will not find many outside of Ubuntu and Ubuntu based distro’s. Big exception is Linux Mint, they do not support Snap applications by default due to concerns about centralized control and potential issues with package management.
Besides these concerns there are also reservations about the number of applications Canonical is packaging and especially the package size and the use of local loop devices to mount them. I share this view because one of my Ubuntu desktops does show this. Just 2 installed by myself, 19 snaps in total installed and using 39 /dev/loop devices. Enough reason for me when I use the df command to add a | grep -v “/dev/loop” to hide them. Canonical also package quite regular applications like Firefox and Chromium as Snaps while other distro’s don’t. And Canonical is pushing for even more snaps instead of regular .deb packages. All in all for me reasons enough not to update my Ubuntu 20.04 desktops but to switch to good old Debian.