The article shows that it takes 15 clicks to install a browser, pin it to the home screen and make it the default, and claims - without evidence - that changing the default search engine is just as hard.
And honestly, I agree with them. I'd very much like a way to integrate my chosen search engine into the Android search subsystem. I actually seem to recall this being possible on older versions of Android, where the default search widget would allow the user to pick a search "lens", say Files, Music, or eMail for example, alongside that of Google Search.
So I think there are two issues here; the shortest path and the "I do this once every 2 years" path. You know, kinda like a perceived loading time.