Yep. A ton of proprietary software (like anything from IBM) supports only RHEL or SLES.

If you open a support ticket and say "Hi I'm using Debian/Arch/Nix" they will just laugh and close the ticket.

How about Ubuntu?

For big enterprise software I'm around no Ubuntu is supported.

SAP: https://community.sap.com/topics/linux/supported-platforms

PeopleSoft/Oracle RDBMS: https://docs.oracle.com/en/database/oracle/oracle-database/1...

Right, but I think the OP's question is why are you using RHEL compat instead of just getting licensed RHEL. In your example a company is already fine with paying full price for major engineering applications why wouldn't you do the same for your underlying OS.

I've seen it done, although small-scale, many years ago.

But yielding that point would mean that RH/IBM would have you over a barrel on pricing. Probably why Suse is forcing the issue.

P.S. and Oracle is piling on ...