The parent comment gets this a little wrong, but there is truth to the data collection aspect.
An increasing number of physicians have to be part of an integrated health network in order to get competitive reimbursement rates. Those networks upload individual patient data to state exchanges which in turn have started to upload to nationwide databases.
The rollout of this is staggered and uneven, as of a couple years ago when I stopped working at a company with its own electronic health record product.
As a sibling comments correctly notes, the CMS bonus (or absence of penalty) does not depend on direct uploading. It does, however, depend on using a system which has the capability of doing that uploading ('sharing').
Finally, I saw over the past 10 years a giant increase in the number of records audited by health insurers. Those audits involve giving the entire patient file to the insurer.
I'm waiting for the day one of these large databases gets compromised and everyone acts shocked that the data was being collected.