Wireless spectrum is limited and either exclusively owned or subject to congestion. Dedicated ine-of-sight direct links are possible and avoid some broadcast problems, but still have property rights issues (they manifest a little differently, since you can smoke a connection without establishing property rights to the whole route, but then you are at risk of someone on the route interposing a temporary or permanent obstruction at any time.)

The existence of wireless connections does not change the fact that broadband last-mile service is a natural monopoly.