One key factor not directly mentioned in the article is the simple alignment of financial incentives when electricity distribution was privatized. Before privatization, the agencies responsible for collecting electricity bills had little incentive to actually perform the collection. When coupled with rampant corruption, you get a situation where a lot of bills are either getting unpaid or not even being generated and just being written off as transmission and distribution losses. Switching to private distribution immediately aligns the incentives of the distributor to actually bill their customers for the electricity they are using. None of this is meant to take away from the value of the technical and policy work that led to improvements, and I'm sure all of the factors called out in the article also contributed to this change.