Comment by chrisweekly

This matters. Beyond performance (a universal good), the definition of "good" UX is strictly dependent on the user. Fintech platforms for traders who open a multi-window thick client application(s) and spend hours in it every day have little in common with consumer mobile apps designed to hold your attention for maybe a minute. It's mind-bogglingly lazy to choose something like MUI (Material UI) as if it were some kind of reasonable foundation irrespective of context.