If anything, it is surprising that the LLM is so bad at stealing a ready-made RP2350 design! There are plenty of easy-to-find tutorials like [0] and [1] that handhold you through the entire design process, and a simple search will give you dozens of design files for open-source boards.

At this level of board complexity you almost have to try to make it completely non-functional, so although it is nice to see it in practice I am not exactly surprised that a LLM with a decent bunch of assistance managed to do it. But there's quite a gap between the equivalent of poorly copying a "Hello World" from StackOverflow and making actual production-ready boards.

[0]: https://pip-assets.raspberrypi.com/categories/1214-rp2350/do...

[1]: https://jlcpcb.com/blog/how-to-design-layout-with-rp2350

There is very little sources compared to software and with hardware you can't really afford too many errors

You have to be more specific about what you mean by design. The models are excellent and the netlist and the components along with tradeoffs.