Two factors IMHO / experience: recruiting, and the ability to push on.
Being great at Recruiting. Recruiting is incredibly hard. Most of us eventually sort of give up, and settle on key hires, or just keep doing a specific role ourselves. And there is always a hotter, better funded start-up than yours.
But the best founders just find a way. They are relentless in recruiting. They find a way to attract better and better talent to their brand-less start-up, somehow. That’s the one way you get scale after $1m-$2m in ARR or so. More on that here: Post-Traction, You Need to Spend 20% of Your Time Recruiting | SaaStr
Finding a way to push on. Especially, every 4–5 years. Everyone gets tired around Year 4, and then again around Year 8–9, etc. etc. Running a fast-growing company is simply overwhelming. It’s constant stimulus, 24x7x365. In the beginning, that’s great. But you can’t be in wartime mode all the time. It weighs on the best of us. This is why you quietly see so many start-ups sell around Year 5. The founders are simply tired.
But the best ones not only recruit the VPs and teams to help them be less tired — they also simply push through that barrier. They have faith that it will get better, and that the company will keep growing and winning. Even when they can’t really feel it anymore, because it’s been so all-consuming, for 4–5 years, just to get there.
They push on, when their bodies and sometimes even their minds say, “It’s time for a rest.” A little more on that here: As The Year Winds Down: Get Some Rest. Or You’ll End Up Washing Out in SaaS in Year 5. | SaaStr
(I am working to get better at both myself.)