Why should they have? Native is a great, if not arguably, the best option.

Because it's a high performance app that thousands of people depend daily for living.

Fast forward to 9:53

...and there he talks about IDE crashes? didn't catch any mention of react.

There is no mentioned of RN at all, it is because Swift works well for Uber. UberEats uses RN because of multiplatform support with their partners.

Uber Everything is hiring iOS developer for logistic service? I used to work in German logistic which uses Java technology and does having lot of issues everyday. Swift would prove logistic industry in a new way and probably use Grand Central Dispatch (GCD) which is powerful. If Swift will supported Corountines after 4.0, useful for server side swift.

Sorry, I find UberEats UI is distracting with animations. It does not feel native to me however I tried to, the font is awkward to read when Sans Francisco font looks much cleaner on native iOS app.

There are no mentions of RN at all, but all the positive points for why they used Swift is probably an implicit argument for using that instead of RN.