The reason there’s a surge now is complex.
1) technology has advanced so huge numbers of these calls can take place at once, and data can be collected on the call—like if a person picks up, they know that’s a live number and they’ll
2) techniques have been developed to collect large amounts of data about people so these calls can be targeted
3) President Obama, like most Democrats, wanted to advance consumer protections. So his FCC passed a law preventing robocalls. This law was challenged by businesses that want to robocall and worked its way through the courts. It was then overturned on a small technicality. The
law could then have been rewritten so that technicality wouldn’t be in it. But it wasn’t, because by this point Donald Trump had become
president and he, like most republicans, is against almost any regulations pretty much, and is pro-big business. So they have no interest in passing a new law protecting the public from robocalls. So no new laws soon. Meanwhile, robocall companies have mushroomed up to take advantage of this period of time when there are so few ways to stop them. There are numerous unscrupulous companies that are basically scams that are using robocalls.
You can hear a lot more about this in the following tech-related podcast: