A neutral Net needs up to twice the bandwidth of a tiered network
This article is a bit dated, but here’s an interesting take on the economics of tiered vs dumb network architecture:
According to Isenberg, the cheapest and best alternative is simply to build out dumb capacity: to “overprovision” by as much as 100 percent. The “bandwidth is scarce” argument plays right into the hands of the major ISPs, which can use it to start charging a premium for crucial services that run across their networks. If they simply built out the networks to the point of abundance, they couldnt make all this extra money.