Yes. In the countries that hunters are popular kids are encouraged to start riding in hunters. They are not allowed to figure things out on their own and are sheltered. In jumper only countries kids are pushed and move more quickly, develop better riding and eventually win more (to be totally honest)
Not really, no. Hunter is only in the US and maybe Canada for the most part. Although they do well on the international circuit, by the logic of hunter impacting jumping levels of non-hunter countries, they should be consistently on top, but they aren't.