This is not for end users, it's for datacenters. Consumer hardware never has fiber ethernet as it is, because there's simply no need. Not only do consumers have no use for that amount of bandwidth, typical hardware has trouble saturating a gigabit connection anyway. Adding more unusable bandwidth isn't going to help. Of course, for some crazy reason consumer hardware often has fiber audio jacks. People are weird.

In core routers, the landscape is entirely different. It's actually very easy to saturate a 40-gig connection coming out of a major interchange, and there are lots of BGP tricks to work around that. Individual ISPs routinely only have one, for political reasons. It would be difficult to saturate 400. (For now.)