I think I much prefer semantic elements like <section> over something like <row>. Calling something a row bakes in presentational information. Something that's a row on one screen size might be a column on another.

I agree. For my blog I don't apply CSS and prefer to let the browser's reader mode perform the styling for me.

But there are categories of application where that is not acceptable. The presentation is a tightly controlled aspect of the application's functionality. If you're designing an application with leptos or sycamore my suspicion is you would fall into the latter category rather than the former.