My web browser doesn't have many permissions to access my data (texts, contacts, location etc) - apps, on the other hand, may have a wide range of permissions and so are open to abuse.

Your web browser runs the apps that contain all of your data, like gmail, google maps, facebook, etc. If your browser doesn't correctly sandbox each site, then vast swaths of your data would be compromised.

Web browsers have the ability to use your location information, microphone, camera, and local storage. Plus the web browser is almost always running.

You may not realize it, but you already trust your web browser to protect you and safely dole out permissions. Why would a next-gen application environment be any different?

Because the web browser is heavily tested and vetted, and I trust it. Whereas some apps I only trust because they have been given some (albeit maybe minimal) checking and validation prior to being allowed onto an app store. If the app I use changes under my feet with no way for me to control that, then I can't see any way of trusting the app.

> Web browsers have the ability to use your location information, microphone, camera, and local storage. Plus the web browser is almost always running.

You don't permit browser access to all that when you visit a internet page. You do on Android if you want to install an app.