The Spark/Chorus breakup has been great.
Interestingly the changes internally is great too (I didn't work there but in a tangential business). When there is vertical integration like in old Telecom lots of good business opportunities are abandoned to preserve business activity in other areas.
With separation, that conflict of interest disappears.
E.g. telecom wouldn't roll out fibre to the home because it directly completes with their entrenched copper line retail business.