Future Valuation, page-97

If the new smart cities in China are going to have fibre optic cable connections for internet what is the advantage of a in- home set top box/router with a 4G sim card installed?

I have been puzzled by this and research has not helped me.  Anyone who attended meeting may be privy to info-if so please share.

https://www.broadbandchoices.co.uk/ask-our-expert/can-i-use-4g-for-home-internet

https://www.techinasia.com/china-top-world-fiberoptic-broadband-penetration-2017

I know I am not the smartest tool in the shed when it comes to technology so if someone can enlighten me I would appreciate it.