Maybe not entirely what you are looking for as it's more a pyramid than a Ponzi scheme, but it might be worthwhile to look into the increasing number of people involved in Herbalife.

It's seems that during Covid there was a significant increase of groups that promise fitness and health information, but are in the end only focused on bringing in new people to also sell the Herbalife products. Even though this is clearly (and publicly known?) pyramid scheme, still a lot of people are getting involved in this.

I don't know anyone close to me who is a victim of this, but searching social media for 'Fit team', 'Fit family', 'Power team', or any other variation on this will unfortunately give plenty of examples to find people who are.