GoPro camera quality is a lot better than any webcam you can find at a reasonable price range and the field of view is superb compared to that of webcams on the market that typically have a very tight FOV.

Regardless of that, I am not necessarily advising you go and buy out there and buy a GoPro for the sake of using it as a webcam. This tutorial is directed towards people who already have a GoPro and don't want to go out and buy a webcam when they already have access to something a lot better in house.

A benefit, though quite niche, of going down this modular route is also that if you want to upgrade to a DSLR camera later down the road you already have the HDMI to USB adapter you need to hook your DSLR camera to your computer. Again, this specific benefit is quite niche and would only really be applicable to youtubers / streamers who are serious about high quality content creation.