I remember back when Scala was still on version 1, the official/recommended IDE was Scala IDE, based on Eclipse. Eclipse was already a mess at that time, and people were abandoning it in droves even for Java work, but (bizarrely) Scala IDE was endorsed by Odersky.

Get this: refactoring -- critical for a language like Scala -- was totally broken on Scala IDE. Completely, unusably broken. Like, you changed the name of a function and the IDE inserted nonsensical garbage that didn't compile or even follow syntax rules everywhere. This situation went for long enough that most sane people migrated to IntelliJ. This was back then, no idea what the situation is now or whether Scala IDE still exists.