It is so weird to me, as someone who entered computing before mice were widespread, that we've just let all the interface designers remove keyboard support.
Even mouse-centric platforms like the Macintosh used to have fairly comprehensive keyboard navigation...
It's not weird at all. Keyboards are an obvious power-user mechanic; you have to memorise how to navigate different programs differently, and really even just memorising one program is quite an ask. It is infinitely easier for the average user to work with between one and three input buttons and their eyes than it is to memorise 40 hotkeys + modifier key combinations + chords + modes, so it's simply common sense that as computers expanded from a niche serving 100k nerds into something serving billions of humans, interface design priorities would change. Nerds didn't have the ability to 'let' interface designers do anything; interface designers can just ignore nerds because normal people outnumber nerds by 10000:1.
Even mouse-centric platforms like the Macintosh used to have fairly comprehensive keyboard navigation...