Most reasonable people want support for both keyboard and mouse-based navigation. 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?
Same with some web forms where hitting enter in a text box does nothing. I expect it to submit a form, but very often, it does nothing.
Because people were triggering it by accident all the time. Firefox and Safari don't navigate back on backspace either.
Enter only auto-submits if there's a visible submit button or if there's just one input, and that behavior goes back as far as I can remember.
About enter to auto submit, i've been running into this problem more often where some web frameworks just ignore the Enter key. There is a submit button, but i cannot trigger it via the enter key.
It's also far less likely to be accidentally typed while trying to fill in a form and fumbling the tab navigation.
It should have been Ctrl-Backspace or something.
Because alt+left is a better choice? Really f**ing annoying when some dumb javascript removes focus from a text box you're editing and the page navigates back.
I can kinda get that one.
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.