MacOS has intentional holes in keyboard support. You have to go into settings and turn on a config for keyboard navigation to reach all elements. Apple intends for most users to navigate with a mouse.
It’s in the accessibility settings.
https://support.apple.com/en-za/guide/mac-help/mchlc06d1059/...
I cannot think of a single reason these would be disabled by default other than Apple stubbornness.
This is the company that popularized the mouse and GUIs, why are you shocked?