This is part of the human condition. Goods don't magically appear out of thin air (at least not yet) - they're created by directed action, i.e. - work. By your definition, every human that exists and have ever existed is/was a slave.
Not every human has or had to work in order to have their needs met. The elites have always existed and it seems they will continue to exist.
Of course, technically you're right - there will always exist a minority of people who were so wealthy (and lucky) that, even though they didn't care about wealth preservation, their wealth didn't run out before they died. If, in addition, these people inherited all their wealth (as opposed to doing any work to obtain it), then they are the (only) non-slaves by your definition, proving that not EVERYONE is a slave.