A CentOS Stream release only gets updates as long as its equivalent RHEL release is in its "full support" period. In practice, this means that the support duration is cut from 10 years to 5 years.

Additionally, CentOS Stream updates often lag behind RHEL updates. This is because Red Hat won't commit an embargoed security update to CentOS Stream until after it ships in RHEL, so the developers responsible for the update will sometimes forget to commit it to CentOS Stream until a week or two after it's shipped. You end up in a weird position where you get most updates faster than RHEL users, but you often have to wait to get critical security updates. I would be wary about using a system like this in production.