4G speeds is pretty much the state of the art in production ready systems. While there is a lot of speed available on LTE, once it is shared across a reasonable number of people the performance drops. This is why bandwidth caps are so tight on mobile networks, they can't have all their subscribers pulling 200gb of data a month, else everyone is going to get DSL 1 speeds.

This problem is a fundamental issue of RF Spectrum, and these problems tend to be addressed by blue sky research that occurs at a university.

Google is trying to address this in the most cost effective manner possible... google fibre. Wireless is unlikely to be any cheaper then simply rolling fibre / copper to every home.