In my experience I spent a lot of time on design nowadays. It turns out I did that in the past too I just had quite a lot of time to think that through slowly while hands were doing vim stuff. And good design is hard. And somewhat subjective. But mostly just hard, pretty sure in some time agents will get better at it, but for now it's still something they can't do well at all.
And by design I mean all of it: UX, look and architecture.