No amount of trying to be careful that can prevent anyone from fall project, you may do your possible best to do a background check on a project, some still turned out to be a scam because any project can easily change.
As Long as this environment remains unregulated, scam and fraud activities will remain constant, even in a the outside environment of traditional finance, there still exist some numbers of reported scam talk less of here that's not watch by the government, they might be doing privately but since crypto are pseudonym in nature, you can't trace all the bad actions in this place.