Or people who don’t clip their nails as short/regularly as some of us do and type straight down, instead of with the pads of the finger (for instance if you say

Or people who don’t clip their nails as short/regularly as some of us do and type straight down, instead of with the pads of the finger (for instance if you say closer to the keyboard than they recommend). Over the decades I’ve seen a lot of keyboards with this kind of wear (though not as bad perhaps) from people in one or both of those groups, even on old school real switch keyboards where the keys are thick as hell.