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.