Along with the other reasons, Badger is not that great. When you have the funding and presumably the developers they have, it makes sense to do something better.
Its issue trackers. There have been sad bugs going on years deep into the project. Maybe they’re all mopped up in 2022 but I wouldn’t count on it. Its design does well on a certain usage profile at the expense of mixed read/write or other workloads. Cockroach has more money and could throw better developers (more experienced) at the problem. Haven’t looked at Pebble though.