Being on this thread for a while, I often see requests about ready marketplace platforms. A lot of platforms focus on typical online stores first, and there's no information about marektplaces. So, I took some time and researched the two most common solutions: Sharetribe (research on pretty much everything) and Shopify (took me forever to research the documentation).
P.S. Analysis of other 15 platforms is coming, including Magento. Hope I can be helpful.