I sign in to video calls using my browser every day. Saying video/audio requires an app beggars belief.

Privacy is the opposite of what you get with an app. Privacy? Really?

Local storage is available to browsers. Office 365 literally functions in a browser with full access to local storage.

Anything processor intensive can be compiled to WASM. This isn't 2005 anymore.

So... widgets?

I can see an argument for games, where you want to pre-install a large amount of resources, and maybe have a better i/o story. Even that is a function of convenience over necessity.