Ask HN: Why isn't there a Reddit/Pinterest for resale?

There are many lifestyle / category based mobile buy/sell marketplaces: For example: https://poshmark.com/ - womens fashion https://sobump.com/ - streetwear https://depop.com/ - creatives marketplace https://www.etsy.com/ - maker/vintage ... many more To me, this is like user forums before reddit/subreddits came along. My question is: Why isn't there an app that lets users create, curate, and shop all of these topics in one spot. Each one of the links listed above would be analogous to a subreddit on the platform.