A single existence proof of a thing makes it much easier for others to try, too.

Without an existence proof, a wide-open ocean might be a blue ocean… or a dead ocean.

If it's the latter, there are hidden constraints and costs that likely make it non-viable in non-obvious ways.

But if there's even one existence proof then it implies it's not a dead ocean.

The longer the existence proof has existed, and the more it appears to be thriving, the stronger the signal.