It's becoming a powerhouse and that usually causes problem in the long run if the chemistry isn't present. Or say the need to be hungry enough to attain goals (just like a strong sports team losing against a lower tier team, aka the underdog).

Yes, surrounding yourself with smart people is great, but surrounding yourself with hungry people is another.

Otherwise, good luck and more success to YC!

Attract the best people for building YC companies, yes. Although that is sort of a self fulfilling prophecy. There is so much amazing talent outside of YC or even SV it is incredible. Just have to know where to look.