Nah it's just that it uses blockchain technology for some reason (hype I guess), but it's not coin related. (Blockchains can be used for other purposes than money).
not necessarily, but it can be a good idea to have a distributed, tamper proof ledger of transactions.
that way anyone can provide proof for basically anything to do with the service: payment, drive, location, etc.
it might also have advantages from a security perspective for riders and drivers.
there are advantages, they're not entirely necessary, but they may well be the best option for a distributed network (i.e.: no central server infrastructure, at least not beyond some simple software repository for downloads/updates)
It's the cryptocurrency that keeps it tamper proof.
Any blockchain can be altered they aren't immutable by nature.
What keeps it immutable is the incentive provided and to not cheat so you can get that incentive.
The whole thing is trustless and everyone is working together aligned on the incentive.
If it doesn't cost resources to secure the chain (which get recouped by the reward) anyone could just spin up a bazillion nodes and take control of the chain and alter the records. And anyone could collide to do so with others to benefit themselves by altering it if they aren't risking a reward, or in PoS, their stake.
If it's a small private blockchain to just keep track of data, people could collude and alter it and it could just be a write only dB with a few admins
What Satoshi did, was invent a way to make a digital item immutable, that was the invention. There were no immutable digital items prior to that. A blockchain isn't just immutable because it's a blockchain.
Currently based in NYC, but getting ready for a big launch in Minneapolis in response to the incumbent rideshare companies pulling out of the city in protest of increased rideshare regulation. Big opportunity to seize some marketshare without needing that much startup capital if your better financed competitors are removing themselves from that part of the market.