On Ubuntu the Snaps feel like crammed in.
Like for Firefox I get nagged by notification: "Snap needs to upgrad in 13 days, close program then" or something. Clicking the notification doesn't bring you to upgrade screen.
Then navigating to Applications, Firefox in list is marked "installed", but on clicking the entry it says "Install", no indication it is already there.
Since Flatpak aren't Ubuntu's experience may be even worse.