I’ve been involved with Linux for a long time, and Flatpak almost seems too good to be true:
Just install any app on any distro, isolated from the base system and with granular rights management. I’ve just set up my first flatpak-centric system and didn’t notice any issues with it at all, apart from a 1-second waiting time before an app is launched.
What’s your long-term experience?
Notice any annoying bugs or instabilities? Do apps crash a lot? Disappear from Flathub or are unmaintained? Do you often have issues with apps that don’t integrate well with your native system? Are important apps missing?
I don’t think the size thing is much of an issue these days outside of say IoT or very old computers. Absurd for say a single calculator app to be weighing like a gig or however much Gnome runtime is, but even in that situation it’s not much of an actual problem imo. And once you install anything else using that same runtime, you in a way halved the size of that app.