20 years ago it was the fast lean option when there was Netbeans and Eclipse. Today it's ok, still good feature wise but fast and lean it is not anymore when I've used it for Scala oand Kotlin.
I think they made it modular so only the core module that is needed are loaded and some modules are loaded only if it's needed by a plugin. Also, they have optimized indexing as well. I remember the whole thing slowed down when it starts to index a medium size gradle project, but now it runs the indexing in the background but the rest of the IDE quite responsive.
However, it seems like in general they are moving at right direction when it comes to optimizing the core of the IDE and all other functionalities comes as plugins and you can just uninstall them if not needed. I use the community edition every day and recently I have been using claude code for coding, but I still use debug console most of the time. I haven't found another IDE which is as powerful as IDEA when it comes to debugging a JVM language project.
On my MBP M4 or my Linux laptop, I never get the impression that it's bloat.
Prior to using IntelliJ I had been a Eclipse user and I've never experienced even 5% of the pain I had with Eclipse since moving to IntelliJ.
When everything is going to shite, I welcome with pleasure my yearly invoice from JetBrains, thinking that, at least, there is a company pushing quality software that deserves my money.
IJ is great for JVM langs.
Sure one can cross-use the above, but that's harder.
Still great to have an IDE agnostic Kotlin LSP!