I completely disagree. Look at (old) Reddit which allows for individual styling of each subreddit, or VSCode which allows themes to restyle the editor, as examp

I completely disagree. Look at (old) Reddit which allows for individual styling of each subreddit, or VSCode which allows themes to restyle the editor, as examples of real world products separating style from structure to huge success. Not everything needs that level of separation, but to say that even basic separation is a problem to be solved by jamming everything into the class list is completely wrong.