It's not something that's kosher to say out loud, but there is a huge spectrum of how "good" someone is at founding/running companies. We tend towards, "everyone can do it if they put their mind to it," which I'm not sure is healthy.
Here are some non-quantifiable things that matter:
1. Grit/High Pain Tolerance. People who do not give up, often to the detriment of their physical, mental, and/or emotional health.
2. Structure. People who can organize — whether in their head or on paper — their business. Who is the customer, what is their problem, how do we solve it, how do we find them, why is our thing better than their thing, etc.
3. Prioritization. People who can look at the things to be done and know which are more important.
4. Communication. You have to be able to talk to people. Not talk at people, but with them as an exchange of ideas. Growing your business (sales), your team (hiring), your brand (PR), and fundraising are all reliant on your communication skills
5. Intelligence. The bar here is lower than is assumed. You don't have to be galaxy brained, but basic smarts.
6. Willingness to seek, sort, and take action on advice. You have to ask for help, but not all offers of help are useful or relevant or correct. And then you have to actually do the thing.
7. Giving up control over things you're not good at. It's good to fire yourself when you're bad at something.
You can find a whole mix of these. I know founders with high grit who work on the wrong things. I know founders who prioritize incredibly well but don't have a full structure of the business in their heads and so get blindsided by an unknown unknown.
I know founders who are monetarily tremendously successful that lucked into a market (some of whom were dragged into that market by others), but, were things to take a turn, their boards would fire immediately.
There is certainly a scale. You don't have to be 10/10 on all of them to be "great".
But the thing is — and I think this is something people have a hard time wrapping their heads around — is that when you sum all of this up, you're only increasing your odds. The odds are still minuscule that you will get lucky enough (many times over) to be in a position to have a massive company. There are excellent founders who fail for things entirely outside of their control.