You're preaching deaf ears.

FB Marketplace has crushed all alternatives in many places. But find one where's that's not the case, and be sure someone there is going to lecture you on how THEY don't need it therefore YOU shouldn't use it, or they never buy/sell anything second hand online, but they absolutely know how you should do that how you shouldn't do that, without proposing any alternative whatsoever.

I remember the glorious time when beginners seeking help on Linux were getting answers such as "it works on my machine" or "you don't need to do that, I don't , instead I do blablabla". Same vibe.

Here’s one now.