> When someone says HTML & CSS is terrible I ask them to design something better that lets you represent user interfaces that can adapt across multiple screen sizes, and allow complex layouts that Flexbox and CSS Grid makes possible. It is easy to criticize something if you don't have to worry how you would do it better.

How about Cassowary, with size classes?

I spend half my programming time working on Mac software and half on web software, and I find element layout in the former is infinitely more pleasant. No need to put elements in a specific place in the document structure to lay them out the way I want. No need to change how I'm working for vertical versus horizontal layout. Just pick the dimension/coordinate you want to set, pick the other dimension/coordinate you want it to maintain its proportion to, and you're done.

Apple's implementation got a bad rap, I believe, because the first version of Xcode didn't support it well, the first version of the API was a terrible fit for Swift (which came a couple years after it), and pre-Sierra macOS had a lot of bugs in the implementation. Today, there's no layout system I'd rather use.