Most TLDs run the bare minimum amount of nameservers required by ICANN, specially the newer TLDs. However, hundreds of nameservers scattered around the globe wouldn't help much either, because they just need to have faster responses to the mass of recursive resolvers.
Hundreds of nameservers scattered around the globe with anycast absolutely helps.
The main thing between a DNS request and a DNS response is network round trip time. Actually processing the request should be trivial (especially for .org, but even at .com), the zone file may be large compared to most, but it's all static records, with batched updates. I remember when internic would do updates at midnight, but you might not make it in the batch; mostly I see 5-20 minute delays on changes now.
