Earlier quoted context omitted.
I'm about 3 years into my career. Should I focus on developing my technical or interpersonal skills?
What you think are technical skills is just currency. Your in depth knowledge of this stack or that toolchain will doom you to maintenance when that currency is discarded for the new new. Your interpersonal skills are tied to your cohort.
At the end of the day, a competent developer will great communication is a better position to be in than a great developer with so-so communication in most companies. Maybe different in the biggest ones or where you can have very specialized roles.