I share the same desire of having ubiquitous wireless communication. When travelling in remote areas of New England, where I live, or while going through Boston tunnels, I often wish I didn't lose reception right in the middle of a conversation.
As your chart notes and my experience validates, wireless technologies are rapidly evolving and growing in density, making their design and ultimate success quite challenging. The various wireless technologies need to be engineered and designed to play nice together.
For example, given that our smartphone includes more than one wireless technology – Bluetooth, LTE, and WiFi - engineers need to make sure that they model environmental effects like proximity of user and nearby objects, such as the user's car, to ensure robust transmission and reception.
Through more reliable engineering design practices, we can all look forward to a future with fewer dropped calls.