It's the same major version, so it's extremely compatible. Plus if you run into something that doesn't work the same, you just discovered what's going to break for your workload on your RHEL system when the next minor version is released.

so it's not the same. Which means that it is not equivalent to what centos was. It's highly, but not fully, compatible. centos was "fully". You can't use it to test on the current version of rhel, where with centos you could. You can't say they're equivalent and then start listing the differences that make them not