I'd recommend TypeBox[1] as an alternative, which has a runtime “compiler” for generating optimized JS functions from the type objects. It also produces a JSON schema, which can be useful for generating API docs and API clients if needed.

It also has a companion library[2] for generating TypeBox validators from TypeScript definitions, which I'm currently using in an RPC library I'm working on.

[1]: https://github.com/sinclairzx81/typebox [2]: https://github.com/sinclairzx81/typebox-codegen