How is it easier? You can literally start your React Native development by opening up https://expo.io and scan a QR on your phone.
With Flutter it's super easy, they have a CLI that creates an initial boilerplate for your code that you can compile and deploy to your phone in just a single command with hot reload enabled. I guess it makes it easier even than expo as you don't have to scan anything on your phone :)
Just re-reading the getting started guide for flutter, you need a set of tools, the flutter SDK, xcode etc.
That's not one command.
The same goes for React Native, you need node and xcode for building locally just like with flutter.
I am talking about the advantage expo offers to try React Native without any tools.
Heck you could try it in an iPad only if you'd want.
What really made the difference for me was their CLI to build and run the app + batteries included approach where the router is available out of the box and you don't need to look through some GitHub projects on how to implement routing and authentication in your app. That wasn't the case with RN.
Also, in this setup, all the infrastructure is in your computer, no need for a cloud service like Expo. However, I do agree with you that if you just want to try something simple, it will be easier with it, it's just how much can you trust that service and why would you for something more serious?