I've definitely noticed the same on IntelliJ but weirdly enough Eclipse feels just fine. IIRC both are written in Java, so maybe it comes down to the design of IntelliJ moreso than the limitations of the JVM?
I used Eclipse for a while before switching to IntelliJ around ~2015 and it actually seemed like a vast improvement, not just in terms of features but in terms of performance. It still wasn't "snappy", but I figured I was doing heavy work so that was just how it was.
Fast-forward 5 years and I've been doing JS in VSCode for a while. My current company offered to pay for Webstorm so I gave it a try. Lo and behold it was still sludgy, but now unbearable to me because I've gotten used to VSCode.
The one other major Java app I've used is DBeaver, which has the same problem to an even greater degree. Luckily I don't have to use it super often.
