I think they mean that a webapp is necessary desktop-first. Many websites/webapps are mobile-first. It resonate with me as I’m used to try new services on a (mobile) browser if available and switch to an app only if necessary.

> the premise that “phone screen ==> native app not web app” is rather faulty, is it not?

Okay but that's not what he's arguing, you're missing the point.

There's nothing stopping a website from being usable on a smartphone. In fact, almost all of these apps are just websites in disguise! They use web views to render.

The reason it's an app and not a website isn't because apps are better for smartphones. It's because apps are native code running.

It's also a choice that websites cannot present as apps (PWAs). Apple and Google purposefully did that so they can push users to apps instead of websites, for data farming purposes.