I guess just to provide a counterpoint, I can't remember having had any issues with flatpak on Pop!, including both open-source apps and proprietary ones like Spotify.

How about zoom? Was the worst and completely unusable for anything more than viewing a meeting.

No issues for me--I've run Zoom pretty regularly, including participating in some fairly large meetings, plus screensharing, etc.

Occasionally I need to replug my headset in at the beginning of the meeting to get my voice audio working, but I'm not sure if that's actually an OS issue or not. Either way, it's never taken more than a couple seconds.

YMMV. Firefox is the golden standard, at least on Arch Linux. Never have I noticed it was running on a sandbox. I run Discord, Spotify, Thunderbird from Flatpak without any issue either.

Visual Studio Code is a regular package, just because its use case it not really suited for a sandbox (access to system binaries, libraries, etc.), but I honestly haven't even tested its Flatpak version.

VSCodium flatpak works fine for me. The caveat is that I use the operating system's terminal instead of the one from VSCodium (for things like make test, python environments, etc). VSCodium's terminal operates on a sandboxed environment and I haven't bothered to figure out how it relates to the OS environment that I get from the terminal app.

You set your shell as some wrapper which allow sandbox escape. It works for shell itself, but then you need to apply it to all external utilities extensions use as well and it gets annoying.

Interesting, are there any examples on the internet for that process?

The problem with flatpack is that many apps don't really run in a sandbox. Or at least not in something with isolation features which you might expect from a sandbox.

To be honest, to me the selling point is not the sandbox, is the reproducible environment that's common for all distributions, which is a first in the Linux world, the sandbox is just the icing on the cake.

The other day I pushed an update to some flatpackaged app, and guess what, it's available to all Linux users. Packaging has become incredibly easier for third parties with these kind of technologies.

The problem is the combination of how updates are (often not) done (in time) + no sandbox.

I also am a strong believer that the future for sane desktop PC's is that every program (except the most fundamental core services) of a desktop OS should be sandbox by default. With basically no permission to access any local files or communicate with any other program/service.

It would need some MAJOR changes, slowly step by step. And I had hoped with snap & flatpack we would be slowly transitioning there. But it doesn't really look that way anymore to be honest.

(PS: And it can be done with reasonable UX experience without requiring the user to configure some magic access rules or anything, but it's tricky to get right and it not be fully backward compatible but often changes just need to go into the GUI toolkit (QT, GTK) so it should be possible.