On the other hand, CentOS Stream will be backward compatible with RHEL. Anything that runs on RHEL should continue running on CentOS Stream.

This is simply not true. Please stop perpetuating this. I have already provided evidence that the current Stream kernel is already not compatible with RHEL and that software that runs on RHEL will not run on Stream.

Right, I get that this isn't true for kernel modules.  The kernel isn't subject to RHEL's ABI compatibility commitments.

If you're arguing that I should have said "any user-space software" rather than "anything", then I take your point.