This is what I've noticed too. Intellij has never exactly been speedy, but it had so many great features that it was worth it compared to other slow IDEs like Eclipse. And using a basic text editor like VIM or even VS Code with a big Java project isn't really feasible like it might be in other languages like Python or Node.

However, now it is really bogging down. I'm sure it doesn't help that I've got several IDEs open along with some monstrosity of a "microservice" framework running half a dozen docker services and DBs on an older Macbook Pro, but it's true that app and OS devs tend to use all increases in CPU and ram, and so absolute performance and battery life never seems to get better over the years, regardless of how much the underlying hardware itself has improved.

VS Code is fine with with big projects, I've been using it for 2 years. The language server is Eclipse after all.

Red-Hat is behind most of the Java plugins, so their quality is quite good, there is only the pain to live with Electron.

Not just slower, also energy hugry. My m1 max running pycharm loses about 10pct of charge an hour on their crappy bundled jvm, and around 4% on the latest java17-based ones, but does act weird at times when using them. Its probably down to metal vs opengl. Disappointing.

Since 2020.x it's definitely slower. The addition of jetbrains space doesn't seem to help either and removing the plugin itself makes the whole ide unstable

I wish they would just release a light version, without all the database, spring integration, and other crap. I just want a light language server.

wouldn't community edition fit the bill? Those things you mention are the main difference with ultimate.

Not sure. I moved to VS Code + Eclipse LS and it's such a more pleasurable experience. However, it doesn't support SBT which is the build tool my company uses.

The community edition is definitely enough for sbt projects.

Any reason you're using sbt for Java projects? That's an odd combination. Anyway, I believe Metals is getting close to supporting this particular use case if you want to keep using VS Code.

For some odd reason my company chose the play framework + Java. It's one of the most baffling choices I've ever seen. I've actually managed to get the Java plugins to work with sbt, but it doesn't understand when a Scala object is imported.

Just deactivate the plugins?

Try power saving mode (look in ctrl+shift+a).