What problem does this solve or what need does it fill?

Registering required components is done through try_register_required_components (or equivalent functions in other types). This expects the components as static types in the generic parameters T and R. There's get_required_components_by_id that returns the list of required components as an immutable list.

However, I don't see a way to register required components just by passing component ids. This is necessary for runtime-defined components.

What solution would you like?

Implement a function try_register_required_components_by_id that gets the base component and its required component by id. I don't know how to handle try_register_required_components_with, but there should also be a way to do that.

What alternative(s) have you considered?

I've looked through the code. There's a get_required_components_mut in Components, but that one is pub(crate). There's register_required_components that's also pub(crate), but that one still needs some type R anyways.

So, I'm out of ideas how to get the current public API to do this.

Additional context

All my research happened on the main branch of bevy (82f6f704dad816e91a47cf72664db6289b179c26).