In 2017 I did a short term contract (I was hoping it would become long term) with the Bureau of Meteorology, they were all Red Hat, everywhere, the odd bit of CentOS or even Oracle Linux, and actual desktop Linux users running either Red Hat EL desktop, or Fedora, they also had a tiny little AIX footprint, and whatever Linux O/S Cray run on their supercomputers (I think it’s RHEL based)
Tell ya what - I’d 10,000x rather using anything Linux, than MS Windows… The CSIRO Pawsey supercomputer located here in Perth, is also Cray and running something related to Red Hat… it’s inescapable… Amazon Linux is based on Red Hat…