We wouldn't be in this situation if Brendan Eich had been allowed to ship a scheme like he was hired to do.

Had that happened, we'd be free of the perpetual JS feature churn (and all the weirdness). Performance would have gotten better much faster. HTML templating like React offers with JSX would have happened 15 years earlier. We'd be sending S-expressions over the wire instead of JSON.

As to CSS, we would have gone with the S-expression proposal instead of the current one and promptly integrated it into the language, so most of the modern weirdness around CSS simply wouldn't need to exist.