New pilots don't recognize quality components and don't know other pilots nearby, often spending much more than necessary or waiting days for replacement parts to arrive. Their gear is often underpowered and poor quality.
Existing pilots often spend large amounts of money to keep flying and gear current. Spare gear rapidly depreciates in value with rapid evolutions within the industry. "Bench cleanup" sales clear space to attempt to recapture any residual value.
Items fly thousands of miles all over the world when local pilots are often willing to sell the same or similar item potentially cheaper or faster.
Everyone wins.
Data regarding purchases and your inventory is not shared with Facebook. It does not reside on Facebook Marketplace, etc. It has more privacy built-in than posts and comments than already exists and is limited to the FPV community, unlike anywhere else.
Facebook is only used for login management (storing users and password recovery) as well as providing for a method for you to post your gear and receive comments.
Similar simplified logins will be available for Google, Twitter, etc.