@hacks4pancakes @randomgeek Had to dig into a menu, but I found it. I wonder if the default profile showcase changed? My profile showcase was set to Favorite Game, which doesn't show that stat, instead of the Achievement showcase, but I've also had my Steam account for a zillion years.
Apparently mine's at 30%, which feels too high. But I definitely have a giant pile of games on Humble Bundle I haven't redeemed on Steam yet.