That seems incredible. 16GB of ram to run (presumably windows 10) and Eclipse?

Eclipse, unlike IntelliJ offers "project" view were you have have many "solutions" open at once. Even with multiple Eclipse instances open, it's hard to imagine it consuming so much ram.

Perhaps you had other company-required software running. I was working on relatively largeish codebases and very happy with 8GB of ram until 2018ish.

Regardless, an IDE is more than a text editor, so your claim that RustRover with 4.5GB of ram is inefficient is misguided.