Next 13 not-found page returns 200 status code

[toxic gyro]

When I use app router not-found.tsx page returns 200 status code for all dynamic routes. The most strange thing that if I remove loading.tsx it returns 404 status code as expected

[undone island]

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[sudden anvil]

This seems to be intended behavior (See: https://nextjs.org/docs/app/building-your-application/routing/loading-ui-and-streaming#status-codes)
I would love to see a better description though since I don't understand how it should not affect SEO and also it kind of breaks our alert tooling since it never returns a non 200 code

[turbid moth]

https://nextjs.org/docs/app/api-reference/file-conventions/not-found

[sudden anvil]

I still don't really get why a 200 status code on a not-found page does not (negatively) affect SEO

[turbid moth]

Why would it affect SEO?