I really hope that Firejail becomes more popular at least on par with Qubes OS and to make it more popular hopefully someone can make a Linux distribution based on it. It utilizes seccomp-bpf before eBPF is even a thing, and what a smart programming move with virtually no library dependency. As they always say security is as strong as your weakest link.
Talking about programming, the author of Firejail is most probably the same anonymous programmer who wrote RCP100, a little known slick layer 3 switch/router. The RCP100 codes has been touted as the best quality code ever written in C code alongside Redis[1].