> I have unlimited 10Mbps (~3TB/month if my math is correct) connection that's costing me nothing to fully utilize. Where do I sign up to help debian?

https://www.debian.org/mirror/ftpmirror

> What I'm saying is, "offloading the bandwidth cost" is bullshit because there is no cost.

There is "no cost" if you use a P2P distribution technology. If you want to distribute hundreds of megabytes to each of a million users using some centralized cloud provider, prepare to open your wallet.