> consistently for most of their lives
This sounds like the kind of overly simplified individualistic narrative I used to believe when I was 14. My heroes to me then looked so indestructible. I wanted more than anything to be like them -- a captain of the industry, prolific and indestructible. The problem with this narrative is that it didn't hold up to real world scrutiny as I entered the workforce and interacted with high-performers and became one of them.
> people get the idea that they're actually very smart when they are just _okay_
I think that this is a very intellectually lazy idea. I've found that the people who most believe this idea are those who are objectively "just _okay_" themselves because they don't understand/have ever experienced how effective organizations and people deploy and harness role evolution. You remember that old chestnut about how some people with 10 years of experience just have "1 year of experience, 10 times?" The two often go hand in hand in my experience.
After all, the most effective way to be lazy about your own professional growth is to believe that it's impossible to improve. And for that to be believable for yourself...you have to make sure other people believe it's the case for them, too. The problem with this kind of fiction is that eventually the fourth wall cracks as people see parts of their network leave for greener pastures where this growth is promised and then actually followed through on. I know because I've sold candidates on this exact thing during interviews.
All I'll say is that it's not a particularly hard sell to say "people that think of the world in such individualistic terms are condemning themselves to mediocrity -- we're building something way better than that, come join us." Think about why that is. Our ability to execute talent arbitrage was based on our competitors having the same mental model as yours. It was an arbitrage that worked very well.