Just have the Men's section, Women's section and Junior's section and the 3 winners play each other in a quadruple robin round format (each player plays 8 games) and the winner becomes the next World Champion.Why isn't the World Championship formatted like that?
Why isn't the World Championship formatted like that?
Because it makes no sense.
First, your assumptions are wrong. There is no "Men's" section. There is an open section which, as implied, is open to everyone. Both women and juniors are free to enter. The Candidates places are open for all players. Whoever qualifies, man, woman, junior, is entitled to play in the Candidates. Whoever wins that, man, woman or junior, then gets to play the reigning world champion for the title. The open world champion is THE world champion.
The real action would currently all be in the Men's section. A woman or person under 20 has never been world champion.
A 3 way format would be, perhaps, unfair. If player A lost all their games to player B but put up a fight against player C, then B could win the championship despite a losing record against C.
This format does not allow the current champion to defend their World Champion title, as is usually done.
It's unnecessary. Under current practice anyone meeting the criteria can contend for the title; there's not a "Men's section" which excludes women or juniors.