The ability to add reports that are visible to everyone depends on the application the report is coming from (ticketing for tickets, assets for assets, projects for tasks, etc.) and whether or not you have the permission to add global reports for that application
on your security role. There is a permission to add global reports for each application that has a report source.
There are several permissions, one for each application, to add global reports. The permissions are all named "User can add global reports", but they are under different sections.
For example, if you are trying to add a global ticket report, you will need to ensure the "User can add global reports" permission is enabled under the tickets section.
Please double-check your security role permissions to see that you have the permission to add global reports for the report source you are using.
I hope this helps!