What makes you assume ChowFun is a sustainable and scalable business model? How do you know Uber's 30% commissions haven't changed significantly since you last

What makes you assume ChowFun is a sustainable and scalable business model? How do you know Uber's 30% commissions haven't changed significantly since you last read about them? What makes you so sure Uber isn't constantly trying to innovate in that space to create the most sustainable business possible? That would align the users and and the stockholders, so I'd be surprised if they were pursuing anything so short term as "abusive 30% commissions" (which maybe were just a quick bootstrap idea).