I'm not sure how you jumped from 'similar levels of people brought in also don't have the skills to scale a company and simply optimize for the signals that the people who hire scalers look for' to 'scaling a company isn't a skill and the only things that matters are code.'
What direct experience do you have with this to justify that claim?
Obviously sometimes people brought in are nothing more than sacks of potatoes that make noises, but I think its insulting to the intelligence of everyone involved to believe even a significant proportion of people fall into that category.
It's just a different set of skills to the ones for 'technical founder' and involve things like... organising, collaborating, compromising and socializing... you know, grown up things that leaders are expected to be able to do without screwing up.
Scaling a company is lot more than just scaling the tech.