This isn’t in lieu of WiFi - it’s just a DIY WiFi hotspot with an LTE modem attached to it. The title could be read to misleadingly make the device sound like an LTE base station.
As a former engineer building LTE base stations - the title is extremely misleading.
Depending on the equipment in use, potentially much longer range, higher throughput at greater distances, and because it’s cool. Just a guess on my part.