Ok, I’m going to play devil’s advocate, even though I prefer Flatpaks over Snaps.

• Snaps are compressed and remain compressed on your system so it’s quicker to download and takes up less storage. (Yes the downside is a slower startup time because it has to decompress first. As opposed to Flatpaks that are downloaded compressed, but are stored uncompressed, and take up more storage.)
• I’m using KDE Plasma (v5 on Kubuntu 24.04) and the Discover app updates all my Snap packages without a hitch. And I would assume it works flawlessly un the standard Ubuntu as well. I don’t know about the other app store apps for other distros however.
• Snaps, like Flatpak, has a tool to manage app permissions. Both launch apps in a sandboxed environment and require permissions to be set, kind of like with Android apps.
• Speaking of sandboxing, this leads to problems in both Snaps and Flatpak where applications were not implemented to be run in a sandboxed environment to begin with and may block some features. (I just ran into such a problem with Firefox and its KeepassXC extension which cannot connect to my KeepassXC instance.)
• Also about sandboxes, this actually increases security. For example, the printing system CUPS has known vulnerabilities. Running it in a Snap can stop some of the attack vectors.

Since these are slowly being adopted by developers, they haven’t ironed out all the kinks yet. So it’s important as a user to report problems so they can fix them. Or, to participate yourself and provide fixes if you can. That’s what makes open source software thrive.