If feet can change 30% in 50 years then toes can certainly change that much in thousands. And I'm not even saying it was worldwide, just the people who made those mud footprints. And that 30% isn't even all humans either, it's bizarrely only women.
Evolution can happen rapidly sometimes. Lookup "island rule" or "Foster's rule", which is also about this. Changing environmental conditions can rapidly increase evolution rates, specifically for "size" attribute.
Women's feet have grown 30% since 1960. Look it up. Doesn't mean the trend will continue, it just means evolution can indeed happen very rapidly under certain circumstances, and for primates to keep long toes for a very long time even after coming down from the trees makes some sense. Probably much more efficient to run thru mud, etc.