Mobile browsers lack many capabilities of mobile applications. This is due to the fact that browsers cannot replicate the same native platform widgets as HTML elements. You can try to do this, but it's often better to just use the native widget, rather than try to replicate it. Partly because this requires less maintenance effort on your part, and partly because using widgets that are native to the platform means that they're consistent with the rest of the platform. For example, if a date picker in your application looks different from all the date pickers the user interacts with on their phone, this isn't a good thing. Familiarity is key, and using native platform widgets makes familiarity possible.

User interactions on mobile devices are fundamentally different from the interactions that you typically design for the web. Web applications assume the presence of a mouse, for example, and that the click event on a button is just one phase. But, things become more complicated when the user uses their fingers to interact with the screen. Mobile platforms have what's called a gesture system to deal with these. React Native is a much better candidate for handling gestures than React for the web, because it handles these types of things that you don't have to think about much in a web app.

As the mobile platform is updated, you want the components of your app to stay updated too. This isn't a problem with React Native because they're using actual components from the platform. Once again, consistency and familiarity are important for a good user experience. So, when the buttons in your app look and behave in exactly the same way as the buttons in every other app on the device, your app feels like part of the device.