See the first version this decade of the Wireless Quarterly from Nordic Semiconductor. www.nordicsemi.com is the leading provider of BLE SOC(s), “system on a chip”.
BLE is changing the game in all kinds of unique applications never before thought possible. Note also the release of BLE 5.2.
Commercial 4G LTE-M and NB IoT solutions are now hitting the market in a big way in 2020. The value of Cellular IoT is it allows almost anything to connect globally to the macro cellular network without having to deal with a middle gateway.
Over time Cellular IoT will change as 5G is released. However realized now 4G will meet the huge demand of applications as they hit mainstream in 2020.
Can’t wait for it to be implemented to its full extent.