I dislike snaps for a number of personal reasons, of which includes their non-confinement to process lists, and the very unflexible access control system... As compared to Flatpak. Discord running as a snap is literally almost no better as a snap than as a system package, but I prefer Discord as a Flatpak because I can restrict it from randomly reporting processess running as "Rich Presence" as it does (by default).
Canonical has already moved a few applications to snaps, like Firefox and Thunderbird. There's some things, like steam, as a snap that just does not work very well at all, to the point even Valve doesn't recommend or support it.
Some .deb packages also turn around and install a snap package in its place, which is annoying as heck, too. I've already hit such a package in Linux Mint that I tried to install a system deb package and because it's not actually a real package but a wrapper package it install snap, it failed. (Linux Mint disables snaps and removes the ability to self-install snapd and thus, snaps)
It's supposed to be sandboxed, and while it sorta kinda is, it's not a mandatory thing to require sandboxing, as there's "classic" snaps too. But the way snaps work, technically, is unusuall too. All snaps are squashfs compressed loopback mounted packages that are apparmor constrained as well. Though simple things like restricting access to running process lists, is not constrained like I feel should be, like is normal on Flatpak.
Also, the more snaps you have installed, the longer boot-up takes, and the slower application initial startup takes, overal. This I personally observed.
