By comparison pages have dozens of links, form fields, menus, etc. It’s not that they can’t be navigated with the keyboard alone, it’s that it’s rarely the most efficient way of doing it. Clicking a link will always be quicker than pressing tab X number of times to select it.
You seem to be under the impression that Netscape style navigation is the best a keyboard can do, which makes the argument an involuntary strawman.
Spatial navigation and caret navigation blow a pointing device out of the water.
The car analogy makes little sense.
I'm intrigued because navigating this way makes UI much closer to a touchscreen experience: there's no mouseover, mouseout, focus states.
Whatever, I used keyboard commands for the entire class period; was fine.
Next day they handed me a fine for breaking the mouse. Turns out they didn’t think it possible for someone to use a computer without a mouse.
Took a legally threatening letter to get them to back off.
That's why keyboard usability is important.