In India, i am getting enquires from customers to build the multi vendor marketplace using Shopify platform. I used to ask them why they prefer Shopify for this complicated feature and their answer is, Shopify has unlimited products, unlimited bandwidth, unlimited storage so that they prefer Shopify. Yeah they may be right because Webkul is master in multivendor marketplace. I also tried WCFM in Woocommerce. In my opinion, if you want to build marketplace please build this as platform so that you can enhance the features specific to vendors requirement. I have not tried marketplace app in Shopify so am not sure about the marketplace apps.
I see Shopify as a platform for an entrepreneur to sell the products he makes and sells. It may contain Abandoned cart notification as it may increase his business. It may have a Buy one get one feature that will help him double his business, and if there are a lot of things like this that will double his business then that is the need of this one entrepreneurs.
There are a lot of things called custom feature in the Shopify app now. I have tested them personally. It has an app called Quiz app. wow, Fantastic App. You have a site that sells nutrients or supplement powder. You can use this if you want your customers to easily identify the product they want. That too is available for free. Here is the app link https://apps.shopify.com/perfect-product-finder
App team supported to tweak some CSS which is helpful at that time. If you need help to install and configure please contact [email protected]