Of course there are always people who are trying to one-up or push ahead up the career-advancement ladder... but I've never ever seen a better candidate appear and challenge someone's position directly. If someone started a new job and starting calling someone out for not doing their job as well, they'd be fired pretty quickly. That's just outright hostile behavior.
Granted I've always worked outside of the valley, I guess FAANG positions can be more hostile.
Because new hires vying for more influence in the office has been a staple of the modern workplace and organizational politics for a long time now.