Sure, I can imagine a world where scooters are as common as bikes. But is that enough to justify a $2B valuation for a scooter-sharing startup?
For a 5% earnings yield, they would eventually need $100 million in income. There are probably $100 million in profits in New York and San Francisco alone. So yes, if this works that valuation seems appropriate.
Emphasis on “eventually”. A basic test for valuation sanity is “are the earnings this company would need for a zero-growth valuation possible?”
If we extend "San Francisco" to mean "Bay Area" and estimate that New York + Bay Area have a population of about 16M then if the company manages to get 5% of locals to become regular riders, $100M in annual profit is over $10 per regular rider per month. Assuming sufficient demand is there, consider the number of scooters that would need to be deployed and maintained to provided sufficient density to service this adoption level. Does that $100M in profit still seem probable in these two metros?
The issue is the value of this particular scooter-sharing company here, not the value of the global scooter market.