Does it? If you set up an instance for your local community/city/whatever, and name it something that makes sense for your intended userbase, I think it would be fine.

It goes from “I sold my couch on FlohMarkt” to “I sold my couch on Local Ottawa Marketplace” for the ‘normies’ out there. They’re not going to care about the underlying software so long as their couch gets sold.

Do recommend a DIY local advertising strategy if trying to get something like this running, though - posters at IRL flea markets, adverts in small community papers for antiques and collectibles, crossposts/links to postings on stuff like MaxSold/Kijiji/Craigslist/GumTree/FB Marketplace/[insert online marketplace operating in your area] by first adopters, that kind of thing.

Focus on the current primary use case of centralized marketplace services (buying shit from your neighbours), then introduce the “Oh yeah, we’ve also set it up so you can see postings on Local Toronto Marketplace, Local Kingston Marketplace, Marché Local de Montréal” etc. from there.

I really, really think talking to people in terms of specific instances over the overarching platform/protocol is a way around ‘normie’ confusion about the Fediverse when first trying it, then getting exposure to how it works in practice will help them understand the nitty gritty stuff better. Is this problematic in some cases, like with Lemmy? A little bit, yeah. For something like FlohMarkt? I think less so.

(‘normie’ in quotes 'cause I’m not the biggest fan of the term, but it’s a useful shorthand)