Backend nowadays, especially Web apps are mostly relying on JSON for data and stuffs. So what is even the point to make my life hard on switching to other while the main purpose is still just this, when i could do it easier.
Discussion
https://misskey.io is one of good example out here. Backend is written entirely in TypeScript and could withstand with many online users.
If a service does not have like 10 million users and 10K+ QPS, the choice of language can hardly be the bottleneck. The choice of database is usually more influential on performance.
Because it’s very easy to horizontally scale a stateless backend service and very hard to horizontally scale a database to a cluster.