[arp242]

The difficult part of CSS is that there is quite a lot of it, and that quite a lot of features have weird interactions, and browsers have real bugs surrounding all of that.

Take "position: sticky" for example; a fairly simple feature, and it simplifies stuff because previously folks were doing that with JS.

But also: there are tons of cases where it doesn't work, or where it works in unexpected ways. A few years ago I compiled a issues with position:sticky, and the number of caveats and bugs in both Firefox and Chrome was absolutely bewildering (I'm not sure if I still have the list somewhere).

This is the sort of thing that makes CSS difficult and complex. Originally HTML/CSS was just a simple text rendering system. So much stuff has been slowly bolted on, not always in the best way.

Other than that I do agree with you. "Just align stuff with flexbox" is kind-of my go-to way of doing CSS these days (I never really got around to looking at grid), and it's a massive time-saver over using hacky float stuff. And having one box model for all browsers also saves a lot of headaches. Hell, I read we're finally getting vertical alignment!

But also: there is a lot of complexity that can really bite you in the arse and make life difficult.