> Why is there 2+ interfaces for all system configurations. 1 of which is pretty but incomplete, and the other hidden and terrible but complete?

This is one of the most absurdly awful things in Windows 10. Trying to disable a network adapter requires navigating a maze of useless New Design(r) config pages (where, for example, the ONLY interaction is "set connection to Metered mode"), complete with broken back buttons that take you somewhere arbitrary.