Ubuntu was a notebook-focused end-user distro. Not sure what it is in 2020.
If you never used early Linux or Unix distros, then Ubuntu might seem normal and you wouldn't notice the differences that I'm referring to.
People pay for Redhat if they're using commercial software and want support, like ERP software. The reason for that is since Linux doesn't have an Application Binary Interface (ABI) standard, commercial vendors can only support specific versions.
Top500 cluster owners were pissed when Redhat started charging per server and wouldn't give them a break, despite operating clusters of thousands of cookie-cutter servers.
I forget if I wrote a post on how shitty Linux is compared to any other OS, but the missing ABI and horrific help/man/info situations would be top of the list.
(You know if you're a linux expert and not a fanboi when you can list 10 things that linux completely sucks at.)