This is an incredible generalization. I've very comfortably navigated codebases in the thousands of files of Python with only find and ack to guide me. I've done a lot of C# in Vim, too.

But I can't do the same in Java; at my last job we had thousands of .java files and I was stuck fumbling around with an IDE to do anything. The verbosity and repeated ceremony of the language makes it difficult to search for anything in an effective manner and the distractingly clumsy syntax (inner classes, as an example) made trying to Vim it failure-prone enough that I'd use an IDE just for the red squiggles. Those being in and of themselves concerning at times--I'd often find myself just trying to make the red squiggles shut up rather than concentrating on writing better code. I don't find myself doing that in Scala or C# or even C++.

I would say that if you need an IDE because of the size of your project, the components are too tightly coupled.

(Admittedly, I like what IDEs can do in static languages to catch errors early and improve productivity, but that's independent of project scale.)

Would you call the Linux kernel a large project?