If you do not absolutely require an app on the App/Play stores you could send notifications to the browser. e.g. See these answers for some information on that:
The way you describe this, you could have an app that allows a user to identify themselves to your server and otherwise literally just shows a logo and waits for notifications.
This implies that you want the user to be able to use your web app from within the Android/iOS app?
You could create an Expo app with basically a full screen WebView component that loads your web app inside of it.
Currently IOS doesnt support web push notifications and thats solely the only reason I want to make it native.
Google play accepts TWA which is a wrapper of PWA so I will only have to make it native for IOS. But I dont want to change a lot of my codebase, or change my codebase from next to react native only because of that.
And from what I understand from Expo is more like react native to web and not web to native