High last mile oversubscription is a net good for home consumers, it almost always works out in everyone's favor. The exception is that 1 guy in 10000 that will actually somehow use 20 gbps a day all day every day in some neighborhood and create some drama in the news because ISPs can't be bothered to try to explain why oversubscription is good to everyone who already doubts them.
Or before you can no longer claim that you are delivering 1 Gbps.
Your average residential user does not move that much traffic at all, if you have a traffic chart that's something like 60s SNMP interface bit counter poller interval for their CPE, fed into a time series db, and draw grafana charts for that customer over a 1 day or 1 week or 1 month period of time.
Even when a customer does something like buy several new 140GB xbox games in one day, the actual amount of time that they're really utilizing that link near full capacity in the same 24 hour period is very minimal.
The only caveat is that you need to be able to watch out for the 1 or 2% of outlier/heavy use customers who will really use their link for huge amounts of data. In many neighborhoods there won't be any of those.
I'm not saying this as anti-PON, just that the existing coax improvements are sometimes very sensible and extremely comparable in the current generation. I've architected and deployed several small city G-PON and 10G-PON networks with Nokia gear and it's fantastic for net new and probably the only real option to continue growing 5-10 years from now. That said, if you've already got decent coax for the last mile DOCSIS 3.1 can be extremely comparable and behave near identically at the moment.
