The strongest tournament format in chess asks for three weeks of a player’s month. Very few players can afford to give them.
Classical chess has a scheduling problem that has nothing to do with the quality of the chess. A serious open or round-robin takes nine to fourteen days of play, plus travel, plus preparation, which is most of a month. A rapid or blitz event takes a weekend and pays comparably at the top of the circuit, and streams far better because a viewer can follow a whole game in twenty minutes.
A rational decision
The players have responded rationally. Several of the strongest have reduced their classical calendars to the events that carry rating or qualification significance and filled the rest with faster formats. That is not laziness. The faster circuits are where the sponsorship and the audience have moved, and a professional has to follow them.
The middle of the field thinned
The consequence for the classical game is subtle. The events are still being won by the same elite players, so the top of the standings looks unchanged. What has thinned is the middle: the strong grandmasters who used to fill a classical open are now playing rapid instead, which reduces the depth of the field and makes the format easier for the leaders than it used to be.

