It was a big team that made that game. I know there were 6 full time writers for most of the development, and a pretty substantial art team as well. I don’t expect them to be able to fully recapture that lightning in a bottle that was Disco Elysium, but there was some pretty substantial talent working there. It’s certainly not a given, but it’s pretty reasonable to hope they can do something great.
Ecosia already has more users than Brave Search according to the few sources I could find that even tried to estimate market share for search engines that niche. They’re all less than a percent either way though, and nobody’s gunning to beat the 13th most popular search engine, especially when number 1 has 80-90% of the market according to most estimates.