Why do little kids wear full sole leather ballet slippers?
I don’t think they make split sole for little kids. Or canvas shoes. The split sole has no support and for a toddles they need the support of the full sole. Split soles were invented solely for dancers who were not dancing en pointe on stage to have their arch look good. ( A toddler would not have much of an arch at all at that age even if they end up with ballet feet.) Prior to that, all dancers not en pointe wore leather full sole shoes. Toddlers don’t really do ballet. They do pre-ballet, which just gets them used to some of the names and not much else. They cannot achieve 5th position (that is why there is a third position) and they cannot engage their turnout yet. It is mostly for fun an playing “ballerina”. Yes, a leather full sole can help build your arch by working your foot, but not really in toddlers. They do not really work their feet very much nor should they at that age. It could do damage to their feet.