> The 99.9% of people who don't even know the difference between www and non-www will never directly benefit from seeing www, ever.
You don't need to know the difference to be able to read the URL off, potentially to someone who does.
It's not impossible (though it's not a good idea) for “example.com” and “www.example.com” to both host web content, and whether or not they know or care about the meaning of the domain name, someone accessing one should be able to, in the event they have a problem, be able to read off which one they are accessing to the person trying to help them resolve the problem.
You don't need to know the difference to be able to read the URL off, potentially to someone who does.
It's not impossible (though it's not a good idea) for “example.com” and “www.example.com” to both host web content, and whether or not they know or care about the meaning of the domain name, someone accessing one should be able to, in the event they have a problem, be able to read off which one they are accessing to the person trying to help them resolve the problem.