Stripe Marketplaces isn't actually a product, there are two products, Stripe Connect and then the Trasnfers API. In the Stripe Connect set up every vendor in the marketplace has their own Stripe account and then each vendor is responsible for things like chargebacks, disputes, etc. The marketplace is just authorized to initiate API calls on behalf of the vendor (so the marketplace can handle the disputes and refunds, but the money comes from the vendor).
With the Transfers API, the marketplace just ACHs funds from their Stripe account to the vendor's bank account, so the Marketplace has to handle all the liability.
