Machines have had incredible amounts of CPU and graphics resources for over a decade now. Why are we still defining UI parameters in terms of pixels? Why are windows toolbars, menu entries, etc. also fixed in size?

I have a 15'' FHD laptop; its screen is only 15''. I also have a 43'' monitor on my desk. When I'm at a client, there are always monitors of varying resolutions and sizes free for plugging in the laptop. Everything reports a reasonably accurate DPI figure. Why can't I say "I want 8mm fonts and 10mm window decorations, figure it out"? How do people deal with this?

I just got myself a new, 4K 15'' laptop. Installing Linux on it is next to impossible, I've had to get out a magnifying glass to see what's on the screen. What groups, if any, are working toward a solution? How can I contribute?

Cheers,

/ji