Getting promoted requires the "people skills" to put the packet together and get the recommendations. If you are too eccentric, people will flat-out tell you that when you ask for a recommendation. ("I don't think you're quite ready for Level X, you need to work on Y.") Certainly you can cherry-pick who you ask, but if you have enough people that like you enough to get you promoted, you probably aren't a big pain to work with. I crossed paths with the occasional L8 or L9 at Google and everyone I met was very pleasant and enjoyable to interact with. And smart, it goes without saying.

Not everyone is a perfect angel 24/7 (one of my favorite high-level engineer's hobby was to antagonize our Director, probably decreasing his manager's lifespan by about 10 years due to the stress), but I guess one social skill you can have is knowing what bridges you can set on fire for your own entertainment. (I was also entertained.)

The "eccentric" folks tend to find their own way, outside of corporate promotions. You don't have to be nice to anyone to win a chess tournament or make a popular open-source library. You just do those things, and your work speaks for itself. Those are kind of more narrow areas in which you can succeed and measure, where Big Tech promotions are a little bit more nuanced, requiring not only technical excellence, but some social skills and navigation of corporate politics.