Hello @Heidi, AppImage is the most user-friendly formats of all if you ask me. Just download one file, make it executable, and double-click to run. Done! No package manager or other tools needed. No command line needed either:
The issue you are seeing is because unlike Ubuntu and most other distribtions, Debian does not configure the kernel in a way that allows the Chromium/Electron sandbox to work out of the box by default. But the fix is easy:
https://docs.appimage.org/user-guide/troubleshooting/electron-sandboxing.html
Please ask Debian to allow unprivileged namespaces by default.