Thanks Justin James for sharing your experience. I was also surprised at how much spam I came across.
In regards to the “people problem”, indeed that is a problem that originates from the people since we are the ones who consume the product. However, people are also the ones who built the marketplace. Hence, if designed both “correctly” and strategically, we can also use technology to help us mitigate (not remove) the people problems. People problems will always exist but it is about how we manage it that makes the difference. For example, if the marketplace had a membership fee that both sellers and buyers had to pay, this would change the dynamics of the marketplace, eg. a reduction in those buyers/sellers with no intentions of buying. Today, unfortunately on the Facebook Marketplace there are no consequences and thus no reason for a buyer/seller to care about disrespecting another seller/buyer.