Any place you have this in a point-to-point rig, you could have fiber cables guiding the light and creating a private collision domain, improving overall bandwidth, reliability and security.

The cost of datacenters is not currently constrained by fiber.

Fiber is not free to run. In an open floor plan office with 20 workstations on an overgrown table, you could run 20 fiber pairs (or cat5e cables or cat6a cables), and you could terminate them and connect them, or you could set up one LiFi access point and 20 client devices. The latter is a lot less cable bundle and a lot less labor.

This can be done now with wifi. The question I answered was about datacenters.

There is wifi in datacenters -- usually for the benefit of visiting techs. Not for inside a rack.

Incidentally, if asked to set up 20 workstations on an overgrown table, and it's not a very temporary thing while the office is in turmoil, I recommend finding a different employer.