> These are not rookies if they reached Principal IC, but the most experienced team members ever, yet the author still feels the need to say this.
At this level the job is qualitatively different from what went before - you do start as a rookie in this role, and if you only try to keep doing what you’ve done before only better then you’re not setting yourself up for success.
> Do we need to move up or out?
Not to this extent, no. If you are still a Junior after 15 years, that’s a problem and questions will be asked. But if you want to stay in a role where you keep doing what you’ve done before only better, then that’s generally completely fine and the right choice for many people.