Because, generally speaking, the end users currently have an internet connection with the capacity and (relative lack of) traffic discrimination to pull that content over the internet.
If the boxes collocated at an ISP broke today, the data would flow to users from distant data centers. All that would happen is the ISP and the content provider might end up paying a little more in network costs.
The edge servers in the ISP network would only have the same non-network-neutrality effects if the ISP offered a string-and-soup-can connection to the internet that could not support the service.
The fear is - as it's always been - the ISP's ability to make a remote service effectively unavailable to their customers.
If the boxes collocated at an ISP broke today, the data would flow to users from distant data centers. All that would happen is the ISP and the content provider might end up paying a little more in network costs.
The edge servers in the ISP network would only have the same non-network-neutrality effects if the ISP offered a string-and-soup-can connection to the internet that could not support the service.
The fear is - as it's always been - the ISP's ability to make a remote service effectively unavailable to their customers.