The article mentions industrial applications being the first to use this. What are some example industrial applications where you need a high-bandwidth, low-latency, link that has to be wireless, that WiFi is not good enough?
Another idea is having a completely sealed Li-Fi transmitter in an isolation chamber send experimental data through a transparent port for analysis. (My guess is Wi-Fi would be harder to package for the purpose.) I'm sure there are many other situations where high-speed short-distance transmission would be advantageous...