I think it depends where you end up for your career and how good at writing you are. Sounds like you were already proficient. A lot of people aren’t! I am in a research role now where manuscripts, PowerPoint, and posters are my main deliverables, so writing and figure design is quite important. I work with a lot of younger folks and they really struggle with organizing their arguments through writing and visual design. Practice helps, but at base I think it’s a critical thinking issue. They aren’t dumb, they just know the conclusion but don’t know how to step their audience through from a beginning to an end in a logical and engaging way.
I had to take a technical writing class at one point (memos, patents, manuals, etc) and yea that’s a totally different type of writing that probably won’t help with emails and PowerPoints! I don’t think I’ve ever “used it” but it was eye opening and I have a lot of respect for people who can do that well. I guess (to pull in what you said earlier) this type of writing is just critical thinking for technical exactness where I think the type of communication I do in my job, and what I assume a lot of day to day communication other stem people do either internally or for the public, is more rhetoric through storytelling, which is where I think the gen ed classes really help.