You clearly dont know how many IPv4 Addresses are owned by big hosting and ISP Companies just to make sure they can doublestack their downloads for backwards compatibility reasons.
I literally get a new IPv4 IP every single day from Vodafone, just to give you a hint on that one.
The hosting Technology for Downloads is quite impressive nowadays, that GregTech Download (edit HAHA the autolinking worked by accident even!) is not just hosted on one singular Server, there is a whole Cluster behind it on Dreamhost. At least from what I understood from @OvermindDL1 telling me.