I suspect that much of the demand for more bandwidth is really a demand for lower latency. It's not that there's a real need for 1Gb/s to the user. It's that the latency is too long under load. Some delay is being inserted by middle boxes near the end user with dumb FIFO queuing. This is sometimes called "bufferbloat", but it's not about how much RAM you have in the router, it's about big FIFO queues.

Just prioritizing empty ACKs in the upstream direction can help a lot. If you can't watch video while uploading a file, that's the problem.