> As for the divide between HTML and CSS: to me HTML is 99% semantic. That means I describe the information as it should be described and the rest is done in CSS.

How? Check the code of this first hero header:

https://tailwindcss.com/plus/ui-blocks/marketing/sections/he...

How do you visually group and align elements in designs like this one by only using semantic elements? I agree there's a few things in there that could be ol/ul/li tags but there's a lot of divs that are just flex containers or flex items. I don't see what useful semantics they could all have when they're mostly for cosmetic reasons.