Nah, I've worked with maybe 2 people I'd say were "10x", or at least 5x, and it was definitely skill.
I used to not really believe people like that existed but it turned out they're just rare enough that I hadn't worked with any yet. You could definitely go a whole career without ever working with any 10x engineers.
And also it's not like they're actually necessary for a project to succeed. They're very good but it's extremely unlikely that a project will succeed on the back of one or two very good engineers. The project I worked with them on failed for reasons nothing to do with us.
I used to not really believe people like that existed but it turned out they're just rare enough that I hadn't worked with any yet. You could definitely go a whole career without ever working with any 10x engineers.
And also it's not like they're actually necessary for a project to succeed. They're very good but it's extremely unlikely that a project will succeed on the back of one or two very good engineers. The project I worked with them on failed for reasons nothing to do with us.