But to be honest? I think CSS was fun for a while, simply because all the stuff mentioned in the intro of the article removed many of its pain points. Flexbox, Grid, the is selector, cascade layers... all of this stuff just lets you simplify your CSS down to something that actually makes sense rather than a big ball of mud and browser hacks.
I will say however that I've never really got to use those fancy colour properties though. Feels like every time I've worked on a website or app for any remotely large company, the design team had some set in stone idea about what the branding should be and would accept zero deviation from that in terms of what colours could be used for text, backgrounds, etc.