I might age myself out here, but, does anyone take influencers at face value, for anything at all, but especially for anything involving money?

Isn't everything these days? It's all gotten so gross.

Would it matter if the bets were real and they picked the 0.00001% big winners to feature in the ad? Would that be less fraudulent in any meaningful sense, would it have a different impact on the world?

Is the real crime here that they were too lazy to lie with selective facts?

Would a prosecution have high chance of succeeding?

Yes, it is 100% a misrepresentation of reality to fool the general public into joining a platform that condones deceptive user acquisition strategies.