For many of these things we're not talking about a web app though. It's frequently just a form, disguised as something more. I agree that the browser should be stripped back, but none of those things prevent my banks website from allowing me to do a payment.

E.g. your fitness tracking app or your parking app, they don't need any of those features. They can work perfectly fine as simply forms, they aren't "apps".

I know, but my point was that this should just not be a thing. Our web browsers have become way too complicated and then you get outcomes like what tfa talks about.