There might be multiple interpretations. Mine was that the colleague whom management is gaa-gaa about, makes flashy presentations, and seems much smarter and quicker than us, but whose work is usually incorrect and often damaging, is AI.
In Kafka's The Castle, the protagonist is sent two assistants by the local government, and (spoiler alert) they thwart everything he tries to do, and end up killing him.
I missed the twist also. When he said he was surrounded by Juliuses I thought he meant his other colleagues had gotten to their positions by cheating with LLMs to look like Julius.
Re-read the last 7 paragraphs, quoting paragraph[-7]:
> On my side, I tried to forget Julius. But, recently, my boss came to me with a huge smile. He had met the salesperson from a company that had amazed him with its products. Artificial intelligence software that would, I quote, boost our productivity! [emphasis added]
I simply did not follow the transition between these two paragraphs:
> I now have an artificial intelligence software that helps me code. Another that helps me search for information. A third one that summarises and writes my emails. I am not allowed to disable them.
> At every moment, every second, I feel surrounded by Julius. By dozens of Juliuses.
The first paragraph is my situation and I like it, so the second paragraph didn't follow for me. My inner voice had a short mental hitch where I thought "was something missing between those? Should I slow down and stop skimming?" Then my eye jumps to "My boss came to see me. He told me that the team’s productivity was dangerously declining" and I decide "the paragraph before must have been referring to the team members using the AI tools", and I've missed the point of the story.