To continue on the analogy, many people using a VPN wear a mask but they also keep the same unique combination of clothes that they were wearing a few minutes earlier without a mask.
I cannot overstate how much of a pain it was to share 51Gbps of peering with 40M other homes and 60M mobile customers. Luckily they now have made generous upgrades, shoving an additional 15M to 20M customers through a whopping 371Gbps.
Unless of course the network your traffic is headed to has deep, widely open and sufficiently climatized pockets.