In my experience Python is fine. However both Go and Flutter(Rust) are better due to the tools that are available, especially the compilers. Flutter in particular surprises me with how good LLMs are at it. Both might actually be thanks to good documentation. Maybe that they are not VERY fragmented and don't have a lot of baggage.

Frontend CSS/HTML is pretty bad though. Although they can work, it takes a lot of pushing. It's probably normal since they do not actually have eyes yet.