I used to do some OpenBSD ports work, and even got a tiny patch into the base system. I love OpenBSD! I don't have an axe to grind here! But it is not above reproach, and I think this site is overall harsh but fair.
Their 'unusual' approach to security might be a distraction they don't need. But maybe it's the only way to hope to pull it off? Maybe they can't do it the GLAM (Google, Linux, Apple, Microsoft) way with OBSD's resources.
https://freshbsd.org/openbsd/ports?q=firefox
Tor browser bundle is also being updated consistently.