Healthcare is about 18% of the US economy iirc. But if you factor in that managing healthcare is somewhere between a part time and full time job for family caregivers, I bet the shadow labor alone adds another 10% of the full economy.
Ie if healthcare were more patient-centric, huge numbers of people would be freed up to do more with their lives. Just dealing with appointments and insurance and tests, ferrying the unwell person around etc. Not even any nursing type work.