This is close to what Red Hat already does - and seems it might align more potential users. If you're using free CentOS, and get into a jam - there's no-one to call for support, other than forums and your knowledge. But, if you had RHEL proper, and got into a jam - you could call Red Hat, and pay for a support package. They could even charge a high hourly premium for out-of-contract support calls, and offer to upgrade you into a support contract, etc.
BTW the RHEL Docker images are now free.
I feel a lot of it boils down to what we, as humans, know about trust: it takes aeons to build it, but you can destroy it with a single reckless action.
PS: Work for Red Hat; views expressed here are personal, of course.
If you have CentOS and feel like you need paid support from Red Hat, you can convert it to RHEL.