> Web designers want their websites to look a certain way right down to the pixel

I’d say we’re actually further away from that than we’ve ever been. I’m old enough to remember <table> based designs, “best viewed at 800x600” etc etc. These days we have responsive design, adaptive color palettes for dark mode and accessibility, flags for users the prefer more contrast, reduced motion, etc etc etc.

User preference time display is interesting but I don’t think it’s realistic. My preferences can be universally applied without context.