Can you do background services, notifications, etc stuff Beyond just ui
notification
sending intents "The other popular use-case for Intents is to call external components such as a Camera or File picker. For this, you would need to create a native platform integration (or use an existing plugin)."
UI isn't everything for all the apps
If I was choosing between RN and Flutter as something to learn, assuming I had no prior experience in either, then Flutter is probably a better choice. I'm sure there are arguments both ways though, but Flutter is very 'solid' for lack of a better term.