"Possibly younger people don't understand what system administrators used to do..."

System Administrators used to blame developers. Developers used to blame System Administrators. Devops is in part an attempt to mediate between "silos".

Bad System Administrators used to blame developers. Bad Developers used to blame System Administrators. Real Systems Administrators attempt to mediate between "silos".

therego...

Therefore we need a new title to distinguish "Real System Administrators" from server technicians. So, we get "devops" for people who understand both.

Except in reality we get people who are bad at dev and bad at ops pretending they can do both

You get people who aren't very good in every kind of role in every kind of organization. Sturgeon's Law applies to everything, even people. If you have more than 10% of your team doing really well you're ahead of the game.

DevOps role is different because it assumes full product ownership. Typical system administrators are focused on just the infrastructure portions. In a DevOps role you are more focused on the things running on that infra, as well as the infra. It's a more encompassing role than the traditional 'sysadmin' role.

In the olden days before it became fashionable to outsource everything to "specialist" the sysadmin team often had full product ownership.