The strategy is to get you onto a different platform to make instant messaging easier. They are just “advertising” on Lemmy.
Once you’re on a chat platform, they will likely attempt the “Romance Baiting” (formerly “Pig Butchering”) scam: make the target fall in love, then persuade them to send money for things like “travel expenses” or “family medical bills”. Also involves buying crypto.
I’ve updated the post to reflect this.