We cannot say that Uber's IPO was a success. The company closed about 7% down the IPO price.
The main business of Uber is ridesharing but they also Uber Eats as an another revenue segments. The company is now working on its own fleet of autonomous vehicles and also Air Taxis.
As far as the valuation of the company is concerned, it is not worth $75 billions since it is not profitable yet and as the CEO said, UBER may never be profitable