Flatpak's complexity is also a product of trying to function as a single solution to two different problems. Runtime isolation and packaging/distribution are d

Flatpak's complexity is also a product of trying to function as a single solution to two different problems. Runtime isolation and packaging/distribution are different things, and there is no compelling reason for them to be conflated together. How you sandbox the execution of your applications should not be dependent on any particular filesystem layout or package format, nor vice versa. FreeBSD does a good job with this: applications are installed into a standard Unix filesystem with conventional packages and the ports collection. Isolation is then implemented via jails. The Linux equivalent of using standalone isolation layers, like firejail, on top of standard distro packaging, is far superior to Flatpak.