That can work but you have to do a much better job of outlawing all forms of government-protected monopolization and its half-way equivalents. Otherwise what you end up with, are local governments that want to cut deals for extra cash with AT&T et al. Local governments are supposed to not be allowed to cut monopoly deals today, but they still conspire with big telco to rig the game any way they can.
For example?
You can though. The second poles group might need to be taller and more expensive, but there is no reason to be a monopoly.
Multiple, taller telephone poles. Yet another stellar solution from the "free market".