Why we need different Apps , When we used to do everything from one browser ?

When we can do almost everything with a single browser whether we want to do shopping , taxi booking , hotel booking or chatting , why we really need to install multiple App to do similar things and give them all the permission to access my device and privacy.

Do we have some Apps (Browser kind ) which allows you to access multiple apps (read services ) or something in making.

If it comes , how it is going to change the existing market of Android and iOS.