We're implementing it though: about:keyboard in a Nightly build does what you expect, this is tracked in https://bugzilla.mozilla.org/show_bug.cgi?id=2000731 and dependencies.

> Like not being able to change the default shortcuts?

Sure, I would also love if Firefox would work like Emacs or some configurable KDE program, but at least I can access most things without needing to touch a mouse and bulk operation actually work unlike Thunderbird where they basically broke the whole UI a few years back and haven't fixed it since.

Do you know another browser that supports somewhat up-to-date non-Chrome-specific Web features and is better on the features I listed?