HTML is bad. The language itself feels unintuitive and is clunky compared to modern markdown languages, and let’s be honest, your webpage just consists of nested <div> tags.
Yet Markdown languages are far, far more limited in both scope and functionality than HTML is. How do you bridge this gap without making it just as complex?
CSS is bad. Who knew styling can be so unintuitive and unmanageable? Maybe it made sense 25 years ago, but now it’s just terrible. It’s very clunkily integrated with HTML too in my opinion. Styling and markdown should be one easier to use language where 50% of it isn’t deprecated.
They didn’t start by writing a spec with half of it deprecated already. They started with something, and over time kept developing it - and deprecating other parts. No matter what you propose, unless it’s 100% absolutely perfect (and nothing ever is) you’ll end up in the same situation. The only other choice would be to break backwards compatibility, which is obviously not a good thing to do.
And now for my hottest take: ~10+ years ago I saw web building tools like Wix and I completely expected web development to head in the direction using a GUI to create, style, and script from one interface, even allowing you to create and see dynamic content instantly. I’ve seen competitors and waited for “the big one” that’s actually free and open source and good enough to be used professionally. It never happened. Web dev has just gone backwards and stuck in its old ways, now it’s a bloated mess that takes way more time than it deserves.
People say the same about no-code frameworks. There’s a good reason that stuff doesn’t work beyond the absolute basics. If it was really possible, HTML+CSS+JS give you all the necessary tools to build it. You won’t get there with a more limited system.</div>