run0 vs capsudo?

The thing about run0, however, is that it's little more than a thin bit of glue code between systemd and polkit. It is highly opinionated and relatively inflexible, not because of any technical limitation, but because systemctl (and the rest of systemd) already exists and supports all the flexibility in the world.

Put another way: Comparing capsudo to run0 is more than a little unfair, because run0 is the tip of the iceberg that is systemd.