Honest question, if the only thing missing from being on equal footing with UE is a highly specific 3d mesh manipulation, why is there a question as to whether

Honest question, if the only thing missing from being on equal footing with UE is a highly specific 3d mesh manipulation, why is there a question as to whether Rust can do GUIs and games in general. Are you operating on a completely proprietary stack or am I missing something about your comment?