What makes a software engineer a great software engineer?

Hi all,
I'm a non-technical type looking to launch a startup in 1-2 years. I will need a technical founder, but I often hear that a great technical founder makes a world of difference in the chances of a startup becoming successful.
I'm doing the Googles and the ChatGPTs to get as acquainted with software engineering as I can, but I wanted to come to the belly of the beast for the most relevant insights. Thank you.