The lead generation was automated ten years ago ("Hello?"), but the actual scam conversation was not. Until recently, you still had to pay somebody in South Asia better than the prevailing wage of ~$1/hr to have these conversations, as well as set them up in an office with computers and managers, and bribe local police (call it $5/hr of fully burdened work product). If your success rate is ~1% and the average human portion of the scam lasts 12 minutes, you're getting 0.05 successes per hour, and you better be netting an average of $100 per successful scam (accounting for financial clearing issues / reversals!) or you're losing money on every hour worked.

You're correct about the calls, but the ability to talk with the people was the rate limiter. Even if you have many people in Cambodia or India, the scammers still needed to scam more than they paid out. Now you can have AI bots that do the first level of filtering.

Unfortunately scamming is a business and if certain actions become less expensive, I would expect more of them.