Apparently the reason they may need to go to li-fi has to do with the enormous strain on the current infrastructure of the web:

The enormous and growing user demand for wireless data is placing huge pressure on existing Wi-Fi technology, which uses the radio and microwave frequency spectrum. With exponential growth of mobile devices, by 2019 more than ten billion devices are expected to exchange around 35 quintillion (10¹⁸) bytes of information each month. This won’t be possible using existing wireless technology due to frequency congestion and electromagnetic interference. The problem is most acutely felt in public spaces in urban areas, where many users try to share the limited capacity available from Wi-Fi transmitters or mobile phone network cell towers.

The radio frequency spectrum is heavily used and regulated, and there just isn’t enough additional space to satisfy the growth in demand. So Li-Fi has the potential to replace radio and microwave frequency Wi-Fi.

Would you connect to the internet through your light bulb?  I guess time till tell.

thanks to iflscience.com for the great info