You appear to be missing my point, which is that this proposed protocol responds to network congestion by increasing the amount of bandwidth that it uses by a factor of more than 10.

Consider what happens when many clients are using this protocol over a shared transit link and it approaches 80% utilisation, so starts to drop packets at a low rate: all the clients will start batching up larger amounts of history and sending them, which increases the utilisation, which increases the packet loss, which increases the amount of history each client sends... it's a destructive feedback loop that launches a DoS attack against the congested link. The absolute size of each individual client stream is unimportant, as we are merely assuming that the number of clients sharing a link is high enough to congest it. The last-mile user connection is not the worst problem here.