They aren't, unless you want to run untrusted apps outside of a distribution.

Flatpak sandboxing is a thing however, and probably good enough in the meantime.

Flatpak sandboxing is not good and development is very slow.

	▲	mixmastamyk 2 hours ago \| parent [-]
		It's good enough for people running trustworthy apps. Certainly, no worse than your PC. Also we don't need flatpak to be developed quickly.