As someone who tends to write Elixir (which, indeed, doesn’t really require an IDE), but has to sometimes help with coworkers’ Java code (where I just stubbornly continue to use my text editor, because it’s what I know): I’m probably being ridiculous, and wasting a lot of time that learning an IDE would pay back nearly immediately†. I see how much more quickly my coworkers can hack on the Java codebase than I can; it’s ridiculous.
If I was my own employee, and working on Java projects all day, and continued to stubbornly use a non-IDE, I’d fire me, because that level of deliberate time-wasting is basically malfeasance.
† Especially for calculating imports, and constructing type declarations. (Y’know, the stuff that more succinct static languages use compile-time inference to achieve.)