It's true that many people spend 95+% of their time on wifi, but we still need to be reachable when in transit. It would be interesting if there were a super-light cellular package that only offered minimal data/calls. I think this is basically what Comcast is rolling out, using the Verizon network as a fallback. The primary method of routing calls is over your own wifi, and over xfinitywifi hotspots at many broadband customers' homes. As a result, the price is much lower than Verizon.

https://www.theverge.com/2017/8/17/16159084/comcast-xfinity-...