When grandparents start seeing .app urls, they are going to be naturally wary. And they might even avoid clicking them. Then someone is going to ask about them to someone who is only partially tech savvy.
And that someone will tell them that those are safer URLs. And that gets misinterpreted and soon you have people saying they are special approved by google URLs that are guaranteed to be safe.
Regardless of who the article is for, tech illiterate people are going to ask "what is this new URL thing, and should I trust it?"