NextJS now is unecessary complex, and there are things to avoid to make sure everything works fine.

I am not sure why it is so slow for you, maybe you you can try run this boilerplate (work in progress to make it easy to use)

https://github.com/wizecore/boilerplate-saas/

It uses Pages router, comes with local postgres, redis and AWS sqs emulator. No docker, no cloud needed for it to work locally.

Such setup is crazy fast on my mbp m2 pro.