I think that it is common consensus that each frontend-type should normally have an own BFF (see https://samnewman.io/patterns/architectural/bff and figure below).
But what about micro frontends (MFE)? I read that each MFE also should have a BFF.
My understanding is that MFEs are (complete) pages and fragments (which are composed to pages, while a page is also a fragment).
I would agree that each page should have a BFF, because a page is like a normal UI. What about fragments? Does each fragment have its own BFF?