This is a snippet of a article I'll post about it:
"[...] popular preprocessors for HTML out there, have one thing in common.
They replace the angle brackets, then add some functionalities on top of it.
If the symbols of a tag are problems to the experience of developing a frontend, replacing it for something else doesn't fix the problem. Just change the symbol.
Pug, Haml, slim, and some others change the angle brackets by indentation or something else. So now, you have to be careful with indentation and not the angle brackets.
Please, don’t get me wrong, those are very well developed preprocessors that are also very well maintained by very skilled people. They deliver what they propose.
[...]"
Yes. But it truly doesn't have angle brackets. At the moment, the features that make it different from pure html are its feature tags and config tags. For example !doctype, meta viewport are built in. Stylesheets and javascripts can be attached with feature tags. Such as style and javascript, respectvely. It may seem that is not that much for now, but as more features are added it will be handy and rubust. One of the goals are to deliver a better development experience.