Why do you need to scan eyes to proof someone is human?

I think iris scans are easy to fake. You can't tell if an iris scan is real or not. It's just a unique random pattern.

So the proof is that you are standing in front of them, not that you have an iris to scan. So why not just a "I am human" button you can press?

This whole orb thing sounds maliciously misleading. They say they only use it to create an account. Great, so I can just create another account at a different orb location?