busyFirst, almost none of the Chosen Ones are in fact chosen. They're fated, which is not at all the same thing. Usually, they get no choice at all, and neither does anyone else. This often makes for boring stories. The fix for this, of course, is to have someone actually sit the fuck down and pick a hero from a pool of promising candidates. It might not always be the most obviously heroic traits that are needed. Sometimes, dragons are slain by brains instead of brawn.
Next, we have the problem of the Chosen One. The drawback with this approach is that heroism is dangerous work. What happens if your hero gets captured, crippled, or killed in action? Or dies of dysentery? You're hosed. It makes much more sense to have a team who can trade off as needed. One of these days, I really want to write that basketball fantasy piece. Pass the Macguffin!
Lightly mentioned in the original article is the problem that the Chosen One is customarily white (and I would add, straight, cisgender boy or girl, and otherwise socially approved). We do see some that are poor peasants, a few of which are even genuine instead of lost royals. Mostly the Chosen One is an ideal. The only way to fix this bottleneck of representation is to represent other types of character in the same role. If you mess with the role at the same time, you haven't fixed that problem. So we need Chosen Ones who are black, who are disabled, who are genderqueer, etc. We need prince/prince and princess/princess pairings too.
Sure, I love a good story where the hero is ordinary and becomes extraordinary through hard work. But that one solution won't fix the above issues.