You're off by an order of magnitude, because it's a max speed of 4Gbps. Not 4GB/sec. Bits and not bytes. Your overall point is still valid, though. Most users

You're off by an order of magnitude, because it's a max speed of 4Gbps. Not 4GB/sec. Bits and not bytes. Your overall point is still valid, though. Most users will get essentially zero benefit from this and data caps or throttling will kick in hilariously quickly.