So nothing can be slavery if there's any choice at all? By that logic slavery can never exist, because any slave can chose not to work and be killed, kill thems

So nothing can be slavery if there's any choice at all? By that logic slavery can never exist, because any slave can chose not to work and be killed, kill themselves, run, etc. At some point you have to draw a line and say, there is choice, but there's not enough choice to say it's not slavery.