I am sure it works for some - North Carolina is not doing so well:

https://www.washingtonpost.com/national/health-science/in-north-carolina-aca-insurer-defections-leave-little-choice-for-many-consumers/2016/10/14/770f7bb2-9172-11e6-a6a3-d50061aa9fae_story.html?utm_term=.858d2df99bfb&wpisrc=nl_headlines&wpmm=1