No the actual answer is that AT&T never spent federal money on actually upgrading their infrastructure for resedntial fiber service.

It would be natural for everyone to be on an 10Gb XGS-PON standard because it's the latest standard. There'd be little cost difference for an ISP in upgrading stuff with something cheaper.

The actual answer is nobody needs it or wants it.

I can saturate a 5Gb connection no sweat lol. Unified upload/download speeds makes all that p2p tech way the hell more viable.