What is the actual benefit that Ubuntu (or Debian derivatives) achieve by disabling root user?
Everywhere I read, it says to prevent unintentional damages for inexperienced users.
I want to know what exactly, since sudo can execute all commands (that I know/use).
So in what case root can cause damage whereas sudo can't?
PS: I know how sudo works.
So in what case root can cause damage whereas sudo can't?
Since you must usually invoke sudo each time you want to do something that requires privileges, the reasoning is that you will "think before you leap", i.e. not just stick sudo in front of something without thinking for a second what the command you're running is going to do.
With su on the other hand, once you're in, you're in. You have carte blanche (an open license) to do anything and everything, and the reasoning is you might forget for a moment that you have those privileges and if you're unlucky, execute something that will seriously affect/damage your system -- if you did not have su privileges, the command wouldn't have done anything serious.
