Invites are really common on other sites now that a critical mass has been reached where people have invited everyone they know who is interested already and are like selling them, there are already accounts that farm engagement on there like "funny cat pics of the day" or something and it will indeed have some cat pics taken from wherever but the point of the account is to follow thousands of accounts to get followed back, and thereby build a following to sell off. It's an extremely clumsy strategy but it's being pursued often enough that you can't just assume a bluesky account isn't a bad actor. So if that is the threshold then it's already been reached.