I believe a minimalistic server framework (Flask) is an unfair comparison to what the author is complaining about, namely packages that need to integrate into an entire front end framework and ecosystem (React Native). Handling requests (Flask's primary use case) is but a small fraction, and addition to, all of the other things you need to implement and consider on devices that would run React Native.
Examples: camera roll and / or camera integration, contact listing, deep linking _into_ the app, linking _out of_ the app, foreground or background push notification display (and subsequent routing on press), the list goes on and on. IMO, native development, even if you choose to go Kotlin / Swift path instead of react native, is extremely complex.
To be brutally honest, I too can fire up a linux box or container, install flask, and have my simple REST server up in a matter of minutes. The same cannot be said for all the example native features listed above.
Examples: camera roll and / or camera integration, contact listing, deep linking _into_ the app, linking _out of_ the app, foreground or background push notification display (and subsequent routing on press), the list goes on and on. IMO, native development, even if you choose to go Kotlin / Swift path instead of react native, is extremely complex.
To be brutally honest, I too can fire up a linux box or container, install flask, and have my simple REST server up in a matter of minutes. The same cannot be said for all the example native features listed above.