My understanding is that Snap's financing terms have actually been very good. The 2 co-founders each still own over 20% of the company each which is pretty exceptional. I'm fairly certain that some of their financing even involved selling common (not preferred) stock.

A 20B+ exit (assuming that's where it ends up) is a pretty phenomenal success. That's 2 million bucks (well above your target) per basis point. A pretty huge chunk of the org in traditionally highly compensated roles (product, design engineering, and kind of management roll, etc) will do very well.

You are underestimating how big of a success this is (again assuming that the IPO goes well) for Snapchat stockholders.