You kind of can, up to like seed level anyways.

I think the real 50x engineer is a person who is a strong engineer, also does design, innovates, and can build a business like a CEO. That person could actually bring 50x value to a small org.

Reddit famously had a team of four for a surprising number of years.

I myself am the sole developer for a B2B software company with $5M ARR.

I'm not 50x (or even 10x) and don't think those designations are based in reality, but your second sentence doesn't follow from the first.

It might be hard to build an unicorn with a single super developer. But he/she might build a great product to get the company enough funding to grow to an unicorn.

WhatsApp for instance sold for $19 Billion and when it was acquired had an engineering team of just 35.

And I think Instagram had like 12.

Says more about the complexity (or lack thereof) of the product than the capabilities of those 12.

I mean, it was a mobile first app, with a substantial server component and infinite scroll, at a time where very few people were iOS experts.

Sometimes that does happen, though...