first, I would push back against the idea that Uber has vastly increased mobility. It's made mobility slightly less annoying in certain places for certain groups of people. But most parts of the world have had taxis for a long time. You've been able to schedule a taxi for decades, something which Uber just recently added. Prices are a bit better with Uber, but it's unclear if the VC subsidized pricing is sustainable. In places like Cuba and Cambodia the taxis and tuk-tuks have been excellent and painless methods of transportation for generations and often require zero wait and have zero barrier to entry other than the price of the transportation, that is; it requires to smart phone, no data plan, no credit card.
I don't perceive Uber as having done anything other than contribute a level of convenience to transportation. I don't feel as though it's provided mobility to anyone who didn't have it before, it hasn't decreased congestion or pollution. How many lives has it saved? How many people who desperately lacked needed resources has it helped? How much has it decreased dependency on non-renewable resources?
I think companies that provide life-saving resources to people or companies that increase equality are much more important. Creating the technology to get everyone access to clean water or drought resistant crops are some ideas that come to mind.