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.
I work on AWS and interact with a fair bit of Principal and Sr Principals. None are "eccentric." Highly competent, great at processing high volumes of information and context switching, asking amazing questions, ready to help, and really quick to pick up new things, and debug.
I think Sr Principal and Distinguished are achieved by excellence AND tenure. Too much context/tribal knowledge is required so hard for anyone to be effective at a high level otherwise.
To be clear, these people often times deal a lot with operational issues. And they're keeping track of a lot of initiatives and fires. So sometimes I see some lose patience in meetings against managers/leadership. But that's understandable I think given their stress. Happens pretty rarely.
Huh, that’s an interesting point. Personally, when I see “L9 IC”, I assume that the person is an extremely eccentric genius who likely does not work especially well with a team. But I’m not an L9, nor do I work at a FAANG, so who knows.
Those kinds of people are generally stuck at a lower level. L7/8/9 is very much a political game. To get there (generally) you need to make your entire org/company look very good, and generally to make your team look good you need to work well with them so that you can convince them to work on the high impact projects that you identify.
It is nearly impossible to have the impact required for these levels by building a thing yourself. These companies are too big. You can't just say "I built a better database" because even if you somehow did to that you'd need to convince the company to shift to it.
L9s are usually having industry-wide impact and that involves a shit ton of just talking with people and convincing them that your path through the forest is the right one. You need the right ideas, but you also need the skills to convince a whole bunch of smart people, often at other companies entirely, that your ideas are right.
I'm going to guess not often because... you don't get to that level without learning how to work well with managers/co-workers, right?