[snark42]

> but I don't understand why a medium/large business would choose anything but an on-premises setup.

Atlassian is in the process of killing the on-premise small/medium business option, already announced an EOL date.

Move to the cloud, buy a 500+ user solution for a much higher price or migrate away are my choices. Of course I use the local database and have local services JIRA/Confluence talk to so it's not really an option to move to the cloud.

I assume lack of competent on-site staff 24/7, having someone else to blame as well as lower costs are why people choose the cloud over on-premise though.