A thought experiment people might find helpful, when wondering whether it makes a difference: In other instruments that are available with different ergonomics,

A thought experiment people might find helpful, when wondering whether it makes a difference: In other instruments that are available with different ergonomics, pro players spend a long time finding the make and model that "fits that their hands" among other criteria. When I switched from a vintage Buffet Dyna-80 tenor (big finger spacing) to a Yanigasawa 902 tenor (small finger spacing), the difference was immediately noticeable and helpful. Zero doubt about it. Guitarists and bassists have known this forever too and hunt for necks that fit their hands. While there is no doubt that there is a lot more to piano than hand size, there is equally no doubt that certain repertoire is much easier for people who's morphology fits the standard piano. (Which was, of course sized for men).