I’m also seeing a ton of Java, C#, and Go jobs in London. At my workplace, Wolt/DoorDash, all new services are being spun up in Go, where Node.js used to be the default.
Plus, LLMs have gotten really good at Node.js and Python, driving backend salaries down quite a bit. In this age, being a one-trick pony just won’t cut it anymore.
As for LLM's, from what I see the languages that LLM's are most often used for are those with the lower barrier to entry / and those that UNI's and bootcamps teach, which would very much also include Java. However, what I see is actually my salary going up as the average candidate quality has been also decreasing, almost in correlation with the usage of LLM's. So while maybe the junior/mid-level salary goes down, the senior salary, in my observations, has not. And I keep hearing from companies how finding actually capable developers has become harder and harder, so I expect my salary to only go up.
Now, of course, being a one trick pony has never been a good thing, I agree on that (did you assume that I'm a just JS dev?), but I was just answering to your original comment.