Your WiFi.

They clearly stated that getting devices on the same network is non-trivial. Obviously, at a place where no network access exists anyways, neither local nor cloud solutions will work.

If somebody required WiFi in an area of the home where it wasn't already, why not just use a repeater/mesh node? If someone wants their smart appliance online, a few extra dollars on top of a likely three-to-four digit purchase appliance is nothing.