That’s my thinking, too. I’ve recently been using ts-rest.com for a relatively small project at work (<20 API endpoints, NextJS frontend, Postgres). Its been such a joy writing the “source of truth” as API “contracts”, and having everything else just work.
With zero added effort, I get fetch/react-query clients 100% typesafe. Request & response validation on the API layer (which can easily be moved from eg NextJS API routes to Express or another framework). OpenAPI spec. Typescript and Zod types. All of that for free, without repeating myself. I like it a lot.