One repo is actual flags control-like-database.

So instead of controlling flags from a website, you get the benefits of git merge, PR's, reviews, documentation etc without having to rebuild it.

I like the concept since it brings accountability. But it's just a need that larger orgs have, but by that point have likely internally built a flag system and so transitioning is difficult.

We do this at my company and another huge benefit is the ability to test config at a particular point in time. You can even git bisect to find which flag flip caused a regression.

Well I don't think you are doing active development on your flags repo. I think it's just using Git as a database for the what are your current feature flags.