Semantic HTML exists and is usable, most developers just want to make their site look like they want (nothing wrong with that). Problems arise when sites don't

Semantic HTML exists and is usable, most developers just want to make their site look like they want (nothing wrong with that). Problems arise when sites don't use semantic elements, style with bespoke class systems. And functionality or markup can't be changed with CSS, so when that's related to the theme it's quite hard to change.