I wouldn't underestimate Eclipse user statistics. That may sound insane in 2025, but I've seen a lot of heavily customized eclipse editors still kicking around for vendor specific systems, setting aside that Java is still a pretty large language in its own right.
At best, that's subjective, but it's fact that JetBrains is comically far behind when it comes to AI tooling.
They have a chance to compete fresh with Fleet, but they are not making progress on even the basic IDE there, let alone getting anywhere near Cursor when it comes to LLM integration.
JetBrains' advantage is that they have full integration and better understanding of your code. WebStorm works better with TypeScript than even Microsoft's own creation. This all translates into AI performance
Have you actually given them a real test yet - either Junie or even the baseline chat?