[haney]

If you only ever use Typescript and are sure you’ll never need to interact with the code in any other language or service in a different repo it’s fine. But as soon as you need to reuse that backend for anything else you’re stuck building something new.

[vosper]

You can make calls to tRPC endpoints from anything that can send an HTTP request. The RPC format for requests might not be your cup of tea, but it works.

[Supermancho]

Ostensibly, the product isn't as useful as the existing gotos (json schemas, shared libraries, graphql, etc), if you cannot create a shareable schema for validation. The ability to form arbitrary requests is already assumed. If your messages are very complex, you need some tooling.