In your every day interactions,
When you go to the store
When you choose what you want to buy
When you interact with the person behind the till
When you hang out with your friends
When you decide to go out for a walk
When you visit your family
No one forced or coerced you to do any of these things, all your interactions with others were voluntarty, consensual and done without the need for some kind of ruling class.
Whenever you think about asking whether anarchy even works, just remember all the daily intetactions that you and everyone you know goes through in their daily lives and realise that this was all done without goverment.
We already live in anarchy for the most part, everything government related is either unnecessary, could easily be done by regular people or is immoral, involves coercion and theft, thus it should be ended anyway.
So, can humanity live without a master? You do it pretty much every day of your life! You want an example of anarchy working? You need only look in the mirror!