It's not clear that vertical integration is necessarily bad for consumers. For example, Kaiser-Permanente is a huge, vertically-integrated "payvider" which both sells insurance plans and also delivers most of the treatment for plan members. They generally do a pretty good job at a competitive price.

Both the payer and provider sides of the healthcare industry have been consolidating for years. Insurers merged to gain more negotiating power with providers and drive down costs. Providers responded by merging (or selling to private equity funds) to gain more negotiating power with insurers and maintain high rates. Government mandates on back office technology also incentivized provider consolidation due to economies of scale. In some areas now a few major provider organizations effectively control the market and payers are essentially forced to pay high rates in order to maintain sufficient networks. So, the logical next step is for payers to mimic KP by building their own captive health systems. Every major payer is pursuing this strategy to varying levels; it's not just UHC.