alt Hacker NewsPeople here seem to be conflating thinking hard and thinking a lot.
Most examples mentioned of “thinking hard” in the comments sound like they think about a lot of stuff superficially instead one particular problem deeply, which is what OP is referring to.
If you actually have a problem worth thinking deeply about, AI usually can’t help with it. For example, AI can’t help you make performant stencil buffers on a Nokia Ngage for fun. It just doesn’t have that in it. Plenty of such problems abound, especially in domains involving some or the other extreme (like high throughput traffic). Just the other day someone posted a vibe coded Wikipedia project that took ages to load (despite being “just” 66MB) and insisted it was the best it was possible to do, whereas Google can load the entire planet (perceptually) in a fraction of a second.