Why is dbo the only grantor in Microsoft SQL Server? I can't understand why is dbo the only grantor in SQL Server? Or am I wrong?

I mean it as follow:
No matter as which user I am currently loged in in SQL Server Management Studio, when I go to properties of a database under Securables and grant some permissions to a user and save it and come back to Securables: dbo is shown as Grantor for those permissions, which I granted before and not the current loged in user.

Why is it so?

Under which scenario could I see another user than dbo as grantor?

Thanks
Probably because all your logins are sysadmin, and sysadmin always connects as dbo.

Try something like:

create user fred without login

create user joe without login

grant select to fred with grant option

execute as user='fred'
  grant select to joe
revert


select * from sys.database_permissions