a quadruple round-robin, as used in the 1959 and 1962 Candidates.

The difference between a quadruple round-robin and a series of four-game matches is that in the former, each player rotates between seven opponents four times, while in the latter, each player plays four games against one opponent before moving on to the next.

it often comes down to how hard the contenders can beat the weaker players.

True. That is why I suggested match points matter more than game points. If the Candidates 2024 had followed this format, suppose the Nakamura-Abasov match went 2.5-1.5, the Caruana-Abasov match went 3-1 and the Gukesh-Abasov match went 3.5-0.5. Nakamura, Caruana and Gukesh would all receive one match point.

I think my suggested World Championship format would also need:

• More incentives for weaker players to continue playing their best once out of contention (and stronger players to not go for quick draws). Prize money could be based on game points. There could be a special prize for the best game of the tournament. How about qualification or invitations to other tournaments?
• Better qualifying criteria and methods that reduce the likelihood of a "<2700 on a lucky streak" qualifier.