Yes, the users of Stylish, Stylus, usercss.com, TamperMonkey, GreaseMonkey, ... It's definitely not a 'regular user' thing, but I'm fairly sure it's more commo

Yes, the users of Stylish, Stylus, usercss.com, TamperMonkey, GreaseMonkey, ... It's definitely not a 'regular user' thing, but I'm fairly sure it's more common than things like 'r/unixporn', or theming Linux to look like Windows XP or macOS, that are themselves quite large niches.