Good libraries for everything commonly done server side in web dev. Google people write the libraries, and they're used within Google, so even the obscure cases are executed frequently. If your problem is a variation on a common theme, not only can Go probably do it, common LLMs will know how to make Go do it.
Go gives up a little performance in exchange for simplifying some problems that give many programmers trouble. It's garbage collected, which simplifies ownership, and its goroutines can safely block, so you don't have the async/sync distinction. Since LLMs don't really understand either of those issues, this makes LLM-driven coding work better.
Remember, LLM based coding is about as good as copy-pasting from Stack Overflow. It only works well in areas where there's something it can copy and mod. Usually, if you search for names in LLM-generated code, you can find where it located a prototype to copy from.