Supercomputing... Note that Summit changed from RHEL7 to RHEL8 mis-stream. (IBM insisted the system I work on had to do the same on similar hardware because the RHEL 7.9 distribution I could see didn't exist. It allowed more recent CUDA, but that wasn't the rationale.)

I don't know what "system admins use is a completely different stack. Users get an update almost every 3 months" is about. Infiniband is fine, and typically quite up-to-date in RHEL, but you end up having to deal with the Mellanox nightmare, at least for Nvidia GPU support; roll on RoCM. That area is a good demonstration of the practical evil of proprietary software.