What is bearing weight is very high friction between wheel hub & wheel disk. Properly tightened wheel nuts just press strong enough wheel to hub to ensure that friction, they don't carry themselves any sideload/weights (unless they get undone
).
As for "centric" part, it's more about how you get wheel centered when bolting on, to not get wheel bolted off-center/eccentric. Be it via same sized wheel center bore & axle size (or +some spacers with flanges), to make "hub-centric", where it doesn't matter much what shape bolt/nut flanges are and even flat, as stock on some brand cars, may work, or it's "lug-centric", where lug-nut holes in wheel disk and lugnuts are of specific shape, that wheel centers as you tighten them (in proper, star, fashion). In this category are for example our wheels/lugnuts of conical 60deg taper flanges. Ball shaped seats should act in similar fashion.