Why can't usePathname be a server or client hook?

[Browntiger2]

Goals

1. In the past, near everything interactive - were client components
2. Today we are moving to server rendering SSR, SSG
3. This hook (usePathname) has a lot of use cases (in server rendering) such as Breadcrumbs, sidebars etc...
4. On Vercel we sort of can get usePath by using undocumented header, but it does not work localhost and could cause hydrations errors
5. Proposal is to move usePathname to be available on the server

Non-Goals

1. Allow to get rid of "use client" in the layout files, just because we need a path to highlight sidebar or render breadcrumbs

Background

With upcoming compiler it is something that compiler should be able to handle.

Proposal

Get that usePathname working on both server / client components