I strongly believe a lot of the reporting is hyperbole.

If you're going to run an offshore call center for spam, and domestic carriers are locking you out, this is how you'd get around it.

Those texts you get "Hey remember that movie on Thursday?" to bait you into a convo?

Those calls from the IRS telling you to send $2500 in Walmart gift cards?

Those can all come from these en mass.

And the best spot to put them is in ultra dense areas where millions of people live to fly under the radar.

They can have thousands and thousands of SIMs, rotate IMEIs, those can as far as I'm aware bridge physical devices from anywhere and make them appear as though they're here.

Think fake reviews, fake social media, social media bots, scam call center operations, etc.

Could they overload a region? Sure, just like a football game, or major event when everyone calls at once.

That's not why you'd have all those sims though.