Even prior to the merger THP was a deeply siloed company and the merger has just made it worse. For most people you work in one of three companies - Commercial, Senior Products (Medicare), or Public Plans (Medicaid). Some job functions go across all silos like IT.
Like all companies there is a decent amount of "dead weight" here - people who have no idea how to do their job. Unique in my experience here is that a lot of people are micro focused on very specific tasks and anything outside of that just isn't their job. These people can not deal with change which doesn't work out well for anyone in a merger of constant change. Since "big brother" has been watching over them for a long time this has worked but it isn't working any more.
If you do just want to make repeatedly make widgets, with no hope of advancement, you can find a place here. Talent isn't going to shine here though. Don't expect new ideas to be embraced unless you're already at the top.
The politics are unusually active here with far left progressives setting policy. Often these policies are well intentioned but exceedingly poorly executed. If you are a moderate democrat or at all conservative this can be frustrating to be around. Mostly you can ignore it but it comes up fairly often. Nobody wants to get cancelled at work so there really isn't much balance.