Before AI video was good enough, I'd always see collaboration videos where some nurse or doctor would be smiling and pointing to a video talking about some snake oil cure. While many were just a random person wearing scrubs, some were actual doctors that have social media accounts. The real doctor had made a video giving their approval to sound medical advice (especially for stuff like skincare) but that video was modified with snake oil advice pasted over the original clip.
YouTube and Google will do nothing to stop it either. They have pushed this content onto my feed a few times and I blocked the channels.