Four years ago, in January 2018, three corporate giants: Amazon, Berkshire, and JPMorgan decided to set up a joint venture managing health care for their employees rather than buying the same service from external companies (insurance companies and health care companies).

https://www.bnnbloomberg.ca/amazon-berkshire-jpmorgan-team-up-to-lower-hungry-tapeworm-healthcare-costs-1.982558 

After three years, the three giants have given up their initial plan and are disbanding the joint venture.

https://www.cnbc.com/2021/01/04/haven-the-amazon-berkshire-jpmorgan-venture-to-disrupt-healthcare-is-disbanding-after-3-years.html

Based on what you know about insurance companies, discuss some rationale in support of the three companies' belief that their plan of managing their employees' health care on their own would work and be better than buying the service from external insurance and health care companies. What happened in three years and what has led them to give up their plan and shut down their joint venture?