The difference between keeping slaves and having employees is one of degree, not of essential quality. Most people work because they have to, to avoid starvation and homelessness, not because they want to.
So the element of involuntary compulsion remains, but the punishment for non-compliance is deferred and obscured.
It's probably hard to organise a non-cornucopian society without some element of compulsion. But the real issue is how the benefits are distributed, how much free time and opportunity remains after the compulsory work is done, and how easy it is to lead a privileged life which avoids compulsory work.
I suspect that ultimately there's a self-centred moral view in which all transactions are seen purely in terms of personal losses/gains and hierarchies of status, and a wider synergistic moral view in which network effects generate social benefits that also boost individual gains - a kind of social trickle down, where the hierarchies are flatter, the status differences are less extreme, but the culture as a whole has the potential to innovate more quickly and creatively.
It's very hard for someone who lives in the self-centred view to accept that some loss of relative personal status is worth increased creativity and opportunity elsewhere.