I think it's valiant to try to do all of this with semantic HTML elements to achieve the right effects, and try to go for a "classless CSS" paradigm to get a nice looking and functional web app (as a fan of classless CSS myself). But scrolling through the component catalog, it unfortunately feels like it's all over the place and inconsistent with semantic vs basic elements, data tags vs aria attributes, and sprinkling some css classes over some of it.

I do very much like that by introducing aria attributes, the CSS reacts to it and styles it appropriately. As opposed to a full-blown react component library which does all of that for you. It would be a good exercise for developers to think aria-first and let the library just help with styling.

Lastly, I think the best part is that this component library has a native sidebar. So many of these I see and they have a nice web page which showcases all the components and I want to replicate their layout and nav/sidebars but they only focus on smaller re-usable components and not the layout. So that's a nice touch, I think. And, as someone who keeps an eye on but doesn't do a lot of frontend, the fact that a sidebar is an aside > nav > ul next to a main just makes so much sense and doesn't have a lot of cruft around it.