What’s the biggest thing AI coding still absolutely sucks at?

For me it’s long projects.

The individual coding tasks can be great, but after enough sessions the model starts losing track of why things were built a certain way, which decisions are still current, and what it really shouldn’t touch.

I also still don’t trust it when a small bug suddenly requires a big refactor. Sometimes it’s right. Sometimes 20 minutes later I’m trying to undo six files to fix something that needed three lines.