You can go into nearly any state and most countries (I think all of the first world countries and a bunch of second world ones too) and book an Uber.
As long as that stays true and Uber continues to grow outside of the US, Lyft doesn't stand a chance.
If Lyft could light up worldwide scale right now, they absolutely would have. Something is holding them back. It's likely new rideshare laws that Uber spawned due to it having first mover advantage.
Disclosure: I am a Lyft user and deleted my Uber account.