My dad l, who worked in tech / IT his whole life (retired now) l, had a problem with his ISP. Called to report it and the next day they called him back, got him to install ‘remote support software’, etc. He eventually saw what they were up to and pulled the plug. Turned out 2 guys at the ISP were selling support tickets to the scammers.
So the expectation was there—who knows how many people they got before they were found.

Exactly—could easily have been much worse, and anyone without at least a little IT knowledge might not have realised. Kind of shows the lengths they’ll go to now, getting employed at targets etc.