Red Hat cutting back RHEL source availability

Is irrelevant, really. I mean, you're entitled to want whatever you want, but Red Hat as a business is not obliged to make it possible. They've come a long way from the early CentOS days to try to meet the needs of people who don't match their customer profile. If signing up for a subscription and dealing with subscription processes is still too much trouble for you, then there's plenty of other Linux distros that are really good for most use cases.

But if you want or need "bug-for-bug" compatibility with RHEL -- if CentOS Stream and their Red Hat Universal Base Image aren't close enough for your needs -- either meet them where they are or don't use RHEL.

I get that Red Hat's subscription process adds friction. I use their no-cost developer subscription myself for a workstation and server. It adds a little bit of time for me to sign into their web-based system and generate images that are already subscribed. But it's necessary because I want to use RHEL for a workstation for work and my $dayjob has a software requirement that depends on either a specific version of RHEL or Ubuntu, and of the two I'd prefer to use RHEL.

There is a point where it becomes unreasonable to expect Red Hat to make available or allow "bug-for-bug" clones of their *product* with zero cost and zero friction.

The reason people want very specifically RHEL and not CentOS Stream is all the stuff outside the source code that Red Hat adds that makes, say, "RHEL 8.5" attractive but "CentOS Stream 8.5.2111" unattractive. The certifications, documentation, regression testing, and very specific compatibilities that go with RHEL 8.5 but not Stream.

If you're not a customer, you're not entitled to that. Because it's not merely about the source code at that point, it's about a whole lot of other work that is well beyond the software and that costs a ton of money beyond development.

Note: "I want to make some Docker build image...without having to worry" about an account is doable today, if Red Hat UBI has the packages you need. They do make a Docker image freely available based on RHEL that requires no relationship with Red Hat at all. See this for example: https://hub.docker.com/r/redhat/ubi8