Elixir, Golang, maybe even Rust (that one is a hard sell though, there could be a lot of friction at the start and part of it persists even when the project matures).
We can disagree about usefulness I guess. Ultimately Ruby has worked just fine. They didn't report massive issues, and the DB is going to be the bottle neck way before Ruby, so I just don't see an issue.
If I knew I was building a site for a massive load would I use Ruby? No. But I don't think it's a terrible choice either.
