why-did-you-render VS nextjs-rewrite-test

Check out why-did-you-render. It may tell you some more information.

It's a combination of many things, but imo one of the worst is all the footguns regarding state and the rerenders they cause

https://emnudge.dev/blog/react-hostage

It's so easy, that we monkey patch react to debug it https://github.com/welldone-software/why-did-you-render

Plus the vdom... Isn't great, the bundle size puts react at an inherit disadvantage, and the community has a knack for over reliance on bloated packages

When we implemented the MVP of the fintech app, we had a quite complicated form. At that time, I was still young and inexperienced. And eventually, we realized that our project was slowing down. We had to spend additional hours figuring out the reason. We had many unnecessary re-renders because we ignored basic rules related to props in React. I wanted to do everything possible to avoid such situations in the future. So, I added to the project linters like this and an additional starting configuration to package.json to run why-did-you-render. In short, this plugin issues a warning if something is re-rendered unnecessarily and suggests how to avoid it. Also, we included running Lighthouse in headless mode. Some people say that premature optimizations are bad, but for me, it's a principle: do it right from the start.

maybe somethin like https://github.com/welldone-software/why-did-you-render

This might help you out a bit.

I noticed while looking at the profiler the other day that all of our pages were rendering twice on initial load. Then saw that _app component was doing the same. Going backwards, I saw that rewrites in config were causing this. I was able to observe the same behavior on a brand new project, https://github.com/ardaerzin/nextjs-rewrite-test, I created with npx create-next-app. The moment I add rewrites, _app starts rendering twice.