You can either have a broad focus without going very deep into everything or you can specialize in a given area. The later is typically referred to as being pigeonholed into a subject area.
I try very hard to become “the guy in that area.” But sometimes it can be extremely valuable to throw yourself into a topic for awhile to become a bit of an expert. Going deep for a time actually does the opposite of pigeonholing you into a subject.
By going in for a time (6 months, 12 months, 2 years, it doesn’t matter as long as it has an expiration date) you become more rounded. You build yourself a springboard to work from where you can then go out and learn everything else from. You get to learn and grow but with focus.