CentOS stream is not versioned. Packages do not move in lockstep. The documentation is good and accurate if you are on the latest version. What do you do six months from now, when some packages have been updated and others haven’t? What doc version do you use then?

Technically, CentOS Stream is versioned. The difference being it is versioned at the major release, hence CentOS Stream 8, 9, and 10.

It is true there are no minor releases of CentOS Stream, but that's due to how it fits in the overall RHEL pipeline. A minor release of RHEL is just an internal fork of Stream at a point in time before release where it essentially becomes "patch only", while Stream will continue on with its developments.

Big big big enterprises outsource IT to big big enterprise vendors, and they benefit a lot from standardizing on RHEL, because they employ people, who benefit a lot from documentation and tutorials and so on.

I would have thought that all the documentation and tutorials would apply equally to CentOS Stream — as I understand it, the only real difference is the schedule for releasing minor patches and bugfixes.

Is it the case that RHEL provides vastly better, more detailed changelogs for minor/bugfix updates (even to the public without an RHEL subscription) and that's what makes so much difference that an exactly-compatible rebuild of RHEL is useful but CentOS Stream isn't?

Bigbigbig enterprises have bigbig compliance departments, and audits, and so on.

RHEL is entrenched in that world, perfect for IBM (which also lives off those clients).