I’d assume that this should go without saying, but there’s a 99% chance he doesn’t actually believe he’s the World’s Fastest YouTuber and he’s not being anywhere close to 100% serious with his claims. It’s pure showmanship to create an event and promote his business (which is himself). As a ‘YouTuber’ that’s literally his job and apparently he’s pretty successful at it (Full disclosure I don’t follow YouTube and have never heard of this guy... or any YouTuber for that matter). But I still understand it’s entertainment.
The most ironic aspect of this is when people comment about how he (or any YouTuber) is dumb or a ‘tool’. If he’s well-known enough for you to comment about him, then his showmanship tactics are working. It’s all about creating noise and recognition. So anyone commenting about him (positive or negative) is literally proving his success.