Re: Lan replacement
Most factory floors, have drop cabling (mains and comm's). However, I suspect the main reason for greater emphasis on WiFi is because people are lazy and try and do things on the cheap!
So come the office desk re-arrangement, a fixed infrastructure generally requires someone to physically move connectors, possibly purchase some new (longer) drop leads etc. But (non-IT pro's) people will raise the question: why incur these costs when (most) PC's now have WiFi adaptors; then complain because things are (unpredictably) a little slow at times.
My rule of thumb, is that the WiFi is mainly to enable flexible working by laptop users, with static workstations being best served by fixed cabling. Obviously, the really challenging problem is providing power and comm's to the island reception desk in an atrium (so no convenient ceiling) that the office designers insist must be positioned in the centre of the pre-existing solid marbled floor (so has no built-in outlets)...