Are good writers are good theoreticans?
Since you started studying computer science, has anyone spent significant time teaching you how to write? Of your whole time learning, what proportion was spent learning computer science, and what proportion spent learning writing skills?

If your answers to these questions are what I expect them to be, then you need to put time into learning to write. It is a skill, not a gift. It can be taught, and it can be learnt. (I should know. I spent five years studying pure mathematics at undergraduate and postgraduate level without ever writing more than about three consecutive words. When I first attempted to enter my chosen profession, which required a written examination, I failed.) I subsequently put a lot of effort into learning how to write. People in my profession, which is very much based on use of words, tell me that my writing is very good.

For me, the career enhancing book was Barbara Minto's "The Pyramid Principle" that makes the case that clarity of thought leads to clarity of thinking. The logical approach she takes appealed to me as a mathematician, and maybe that might appeal to you as a computer scientist. But there are lots of books.

I suggest it is not helpful to comfort yourself with such thoughts as 'good theoreticians are never good writers, and vice versa'. If you are bright enough to be good at computer science then you are bright enough to learn how to be a competent writer.