The number of times I’ve seen numbers written inside of a <li> that’s inside of a <ul> — instead of just using an <ol> — is deeply disturbing.

Are there real problems in CSS? Of course. But those are problems like, “border-radius should have been called corner-radius,” and “atomic stacking contexts are generated when using opacity,” and “an em isn’t really an em.” Those are problems.
The C of CSS is not a problem. You’re the problem.

Server-side rendering was not invented with Node. What Node brought to the table was the convenience of writing your shitty div soup in the very same language that was invented in 10 days for the sole purpose of pissing off Java devs everywhere.
Server-side rendering means it’s rendered on the fucking server. You can do that with PHP, ASP, JSP, Ruby, Python, Perl, CGI, and hell, R. You can server-side render a page in Lua if you want.

Our consultants had never considered that CSS could do something as fancy as, “show you a thing when you hover over it.”

10 years ago I thought CSS preprocessors were the coolest thing ever and I was incredibly fucking dumb for thinking that.

If that’s the output you expected, either you’re one of the Sass spec writers or you did a double-shot of espresso followed by a Ritalin chaser.

You’re thinking, “But Frank, it saves me on keystrokes! Now I can generate more classes and classnames just based on that list of sizes!”
Bro.
ctrl+c and ctrl+v exist.

Maybe that’s why the front-end world lost its damned mind with React. React was so not-angulary that front-end folks were like, “let’s use it client side, server side, native-side, and the 3 other sides of a damned cube”. Folks decided it was a good idea to Reactify All The Things®.