> For example, why did Edge and possible chrome, remove support for Back via the backspace key? Literally, why remove something that exists and that some people might use?

Because web pages don't preserve element focus well, web was originally meant for documents in the first place, not UIs. If you're trying to erase a character and the focus has been lost, you go back in history instead. It's a real existing problem in poorly designed pages, not a nefarious plot to annoy power users by Google, Microsoft, or Mozilla. It was always janky as hell.