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?
Two issues I have with them.
First the size. Being on a poor internet connection makes downloading them painful. Some apps are 200MB for the apt or a flatpak install 1.5GB! Also doesn’t help with disk space.
Second I often have issues saving files. Some apps use non standard folder location and some still save them to the non standard location even when you select one of you own. Block bench was bad. I’m not sure what causes this, if it wasn’t for the size I would probably spend more time looking for a fix.
Flatpak also installs dependencies, which are shared across Flatpak apps - So yea, the initial download sucks, but native apps actually do the same thing (you just already have the dependencies downloaded).
Also for disk space - If your fs has compression by default, a lot of it gets saved
File a bug report upstream on a per-app basis