Sack Geoff Horth Today, page-38

Some small businesses maybe.

But internet is too important to a lot business's to have down time. Therefor they will like today buy multiple services. Of which fibre will be the most reliable/resilient.

Wireless is a shared medium, that is much more susceptible to interference and congestion. None of the quoted speeds of wireless will be sustained if they boost quota's to fixed line levels.
Something else many people don't realise, beyond a certain density fixed line becomes a better delivery method.