That's his point. With a web app, his experience tells him he can run the code within an environment that he's used to.
With PyQt, he needs to download and install PyQt. When ready to ship, he needs to figure out how to build it into an app that can be delivered to clients.
With web technologies, he knows how to get deliver code in ways it can be loaded in a web browser, and how he can deliver code to end users.
Though to use that web code with Electron, he needs to download and install electron and figure out how to build it into an app that can be delivered to clients.
Yes god forbid anyone ever need to learn something new to do something different.
The web has a lot of great advantages for sure, but native applications have advantages and can do things that are unwieldy and inefficient via the web.
With PyQt, he needs to download and install PyQt. When ready to ship, he needs to figure out how to build it into an app that can be delivered to clients.
With web technologies, he knows how to get deliver code in ways it can be loaded in a web browser, and how he can deliver code to end users.
Though to use that web code with Electron, he needs to download and install electron and figure out how to build it into an app that can be delivered to clients.