No it doesn't, don't cherry pick what fits your narrative. Firefox has vertical tabs, that's it. It's great that Firefox finally has native support for vertical tabs, but its roughly 10% of what I like in Arc/Zen.
split panels, profile switcher, tab groups...
The 90% remaining are UI gimmicks that are irrelevant anyway (mods, custom cursor, free canvas?). Even when Arc was still alive they're useless which is why the browser died (it sucked at doing things that matter). Zen just picked up this lack of focus and make it worse with the solo maintainer situation.