Looks like VC money ran out so the development company is now making an AI product like everyone else. Kind of feels bad because it was the only good Chromium Browser and kind of innovative in it's own right. I switched over fully to Zen like a month ago so I don't really care but it's just a classic case of tech bro tomfoolery where a company only works for hype so they can eventually sell it to someone eventually. Nobody bought this company because people make browser mods on github for free.
https://www.reddit.com/r/ArcBrowser/comments/1gc2fxx/arc_officially_not_getting_new_features_only/
It was legitimately better to use with tab management and the command bar along with a lot of small yet powerful features that just worked. I still used Firefox as my main browser on PC+Android and used Arc only for work/study.
I've fully switched to Zen now which is promising and open source.