Horrible. We're going to end up with three separate languages: CSS, HTML, and Javascript, which will each be turing-complete programming languages with completely-overlapping featuresets, and there will be no clear reason to use one over the other.

Browsers will have to implement support for three PL runtimes. Everything will be complicated and confused.

Everything will be even more complicated and confused.

The sky isn't falling, and nearly everything is trending better, not worse. You can use whatever features of browsers that you want.

There are tradeoffs. Further increasing the barrier to entry for new web browsers benefits the entrenched players and hurts end users by yielding fewer alternatives.

The entrenched are the ones deciding the features. This is their goal

That's what people say of C++ too. Too many features makes it harder to learn a language and ramp up on codebases; they'll have different standards on what they use.

Developers can use whatever features they want, but users can only watch as their computer uses up more and more energy because it suddenly has to perform yet another build step that previously was done on the server.

Is there DOOM in CSS already?

There's a Wolfenstein https://css-tricks.com/hacking-css-animation-state-and-playb...

Maybe in ten years they will finally add enough languages to each one of these 3 languages to make them good enough to compete against Delphi.

Already a thing of past http://www.w3.org/Submission/1996/1/WD-jsss-960822 Netscape Communicator 4

JavaScript Style Sheets (JSSS) alternative to CSS, a "Programmable CSS"

Never got spotlight because stubborn people werent ready to let go of css