Agreed. I recently moved a production app from Zod to Valibot for exactly this reason. I still slightly prefer Zod’s syntax but the performance issues were absolutely killing us.

Not only that, runtime schema validation was also way faster in my last project for larger arrays of complex objects with lots of union types. Went from 400ms to 24ms all else being equal. Since our validation was running on every request for certain reasons this made a huge difference in perceived performance for our users and less load on our servers.