Like the unused bu allocated space in a Vec is basically a `[MaybeUninit<T>]`.

Or in async runtimes you often have an unsized type with an future trait object inlined (through unsized types anyway need a bit more love ;=) ).

Or some C FFI patterns.

But yes I would say in pure rust the use cases for `MaybeUninit` are rare, and the cases where you need pointers to fields even rarer.

Though while rare in comparison to the amount of code not needing it, still needed enough to be somewhere used (e.g. in a dependency) in many projects even if ignoring std.