In many cases I have no frame of reference for the expected code, like React and css. Typescript is perfectly readable, but I’m not really a script kiddie, so I’d go very slow on the React tsx files. The services are probably a slightly faster set of work, especially if I always have unit tests.

If someone was an expert React+TypeScript programmer with decent css knowledge the productivity may be a marginal improvement.

But I haven’t been a full-time programmer in ten years.