I don't know about "on here" because HN tends towards startups and freelancers, but in the US Enterprise sector, Red Hat is what you buy when you want a vendor-supported Linux in your expensive lights-out datacenters.
If you take a look at the Fortune 500, it wouldn't surprise me if Red Hat was in use by at least 490 of them.
Working for one of the hyperscalers as an architect, this is exactly my finding too. RHEL is the standard, everybody runs it. Exceptions are for SAP (SUSE) and some container workloads. RHEL for all the rest.
Yeah it's common in the traditional, established firms. Something about compliance as well as the fact that some of the proprietary enterprise software packages they use only support RHEL.
If you take a look at the Fortune 500, it wouldn't surprise me if Red Hat was in use by at least 490 of them.