I disagree with that. It's harder to tell a story when you have random winners all season long. There is no Hakkinen vs Schumacher, Senna vs Prost, Hamilton vs Verstappen, Verstappen vs Norris, when the season is one big free for all. I think a good F1 season just needs 2 or 3 main protagonist.
You can have two or three title protagonists while having multiple winners. It just requires paying a bit more attention.