If it is that the ROI is just real unattractive for spam calls now... I wonder if the waves are just new people trying to spam for the first time. And taking a little bit of time to figure out that it's not profitable.
If so that's not great. Because there's probably an infinite supply of people ready to waste their money trying get-rich-quick crap.
Whether it's profitable is relative. For relatively little effort anyone with a bit of tech know-how can setup a spam/scam operation. If they also happen to live in a low-income region and target high-income regions, they only need to scam a handful of people a month to get a decent ROI. The amount of vulnerable people is unfortunately high, especially among the elderly.
Jim Browning on YouTube does great work exposing this scum. There are huge call center operations in India and Pakistan, and the local authorities are useless if not complicit.
This will only get more popular and profitable once AI tools get more accessible. There's no need to have a physical location and hire humans if they can just launch a army of bots that have perfect accents and can follow a conversation without deviating from the script. The next generation of robocalls is just starting.
If so that's not great. Because there's probably an infinite supply of people ready to waste their money trying get-rich-quick crap.