The thing most people get wrong is privacy friendly =! private. If you say something publicly (on the internet) you can assume it will stay for ever, if not directly then via some sort of archive. The privacy part of Lemmy/Mastodon is them not collecting data on what you look at to sell it. If you want something private then don’t use Social Media, because what you say publicly will stay public.
“Bro, I’ll trade your food for this fancy piece of paper”
“What can I do with it”
“Trade it for more food with a bigger fool than you”
“I’m in”
(Not saying that you’re wrong, just your argument is stupid)