There are even more of them in the current rules - 7.
The Top 3 was chosen to increase the likelihood that the games will be played. Top 4 and 5 will simply give up, losing their chances.
Ah, I'm talking about a tournament regardless of the rating; too large an advantage could arise due to G+U. If the tournament started today, I would have an advantage of 100 points, and it's possible that the results of the tournament wouldn't matter at all. And I suggested a separate mini-tournament with 5 people.