>, but I don't know that "easy to spot" is a good yardstick.

Anecdotal, but my dog has had a Facebook account for a decade now. He makes appropriate comments and likes too. His profile picture and stats are accurate. Given that FB can detect faces and assign names to them, I assume they know this account is bullshit. There's got to be some aspects of avoidance of their part. Growth is more important than making sure accounts are real, unless people report it.