In our civilized societies we are rich. Why then are the many poor? Why this painful drudgery for the masses? Why, even to the best-paid workman, this uncertainty for the morrow, in the midst of all the wealth inherited from the past, and in spite of the powerful means of production, which could ensure comfort to all, in return for a few hours daily toil? - Peter Kropotkin (1892)
There are other ways, of course, but capitalism is very good at incentivizing innovation. And the complexity of innovation as it typically is these days requires a lot of investment, infrastructure, large teams etc. it's a risk to do all that investment and work on some idea when one doesn't know for sure if it will work or be as useful /popular as you think. If we don't incentivize such investment and effort with a reward such as good remuneration, it won't happen, at least not at anywhere near the same speed. And all those people working on innovation aren't'slaves', they typically enjoy it to some degree. But they wouldn't put in all that effort if it wasn't a job that they needed to do to support themselves. And they wouldn't be able to coordinate such a project and collect required resources without it being through a company like entity. We know government sucks at this sort of thing precisely because there's no drive to push to make things better and marketable; it devolves to politics, and gaming any metrics. I think the main error of your thinking is that although we could reduce our work load and survive - so we could all work less or some lucky people wouldn't have to work, that would slow innovation. As a species, we can use the extra bandwidth that technological advancement has afforded us to make more technological advancements. This actually leads to a better quality of life for everyone. Now, there's still obviously a major problem with the way unfettered capitalism abuses minimum wage unskilled workers and billionaire owners hoard wealth - but I really don't see how we can effectively run a society where people don't have to work, where people just do what they want - and then expect things to keep functioning and even progress.