"One of the most..." doesn't mean "the most". It means there is a group of "the most", which can include a large raw number of objects, but this number is still a tiny fraction of the overall number of things, and his is in that group. It could be the last one in that group, but still in that group. Saying "The united states is one of the most populous nations on earth" doesn't mean it's more populous than China or India, simply that it is up in that rarified group of "mosts".
