What is needed is a easy to setup, widely supported VPN so people can leave their phones/laptops connected to the home VPN so they can access their smart devices. The VPN should be no harder to setup than Wi-fi as current VPN solutions are too much for non technical people. As a side benefit is it could cut down on the shenanigans mobile carriers can pull with rate limiting specific traffic as people could funnel all traffic through their homes connection.
Getting all of the various manufactures to support the same easy VPN standard would be the hardest bit, as the technical side is assembling already existing pieces into something easy to use.