The fragmentation around runtime validation libraries is pretty crazy. The fact that half these comments mention some alternative library that mimics almost the exact API of Zod illustrates that.

It is filling a necessary shortcoming in the gradual typing of TypeScript, and using validator schema types to power other APIs generic inference is powerful. I am optimistic about an obvious leader emerging, or at least a better story about swapping between them more easily, but a bit annoying when trying to pick one to settle on for work that I have confidence in. That being said, Zod seems like the community favorite at the moment.