Why might a too-wide runway be a problem?
The issue has always been human perception.  Pilots are tasked with trying to make great landings.  One way they do that is with peripheral vision.  If the runway is too wide, they lose that extra clue on when to roundout and flare.  They may flare too early and stall the aircraft too high above the runway.  This perceptual clue is more important for tailwheel pilots than tricycle gear pilots.
From the FAA AIM 8-1-5.


Illusions Leading to Landing Errors.


(a) Various surface features and atmospheric conditions encountered in landing can create illusions of incorrect height above and distance from the runway threshold. Landing errors from these illusions can be prevented by anticipating them during approaches, aerial visual inspection of unfamiliar airports before landing, using electronic glide slope or VASI systems when available, and maintaining optimum proficiency in landing procedures.




(b)Runway width illusion. A narrower‐than‐usual runway can create the illusion that the aircraft is at a higher altitude than it actually is. The pilot who does not recognize this illusion will fly a lower approach, with the risk of striking objects along the approach path or landing short. A wider‐than‐usual runway can have the opposite effect, with the risk of leveling out high and landing hard or overshooting the runway.