The FCC has been cracking down on Traffic Pumping (which is what FreeConferenceCall, AOL, NetZero, etc were all created to do) to these prefixes, along with fake ringing that companies including T-Mobile do to make it seem like the call is being connected to these high cost areas, meanwhile the person your calling doesn't ever receive the call (or it gets through after attempting to call for multiple minutes).
Interestingly enough T-Mobile has started giving me a notice before calls to some of these providers saying that I'll be charged 1 cent a minute for the call.
I've reached out to T-Mobile's business team repeatedly on an account that I'm a POC on to get a full list of surcharged numbers, but they are unwilling to disclose this basic information. This kind of stuff is what keeps businesses on Sprint and Verizon, at least they know their NANPA calls will get delivered reliably without surprise surcharges!
I've wondered how that works. In other countries / continents, it's clear when I'm calling a foreign number as the prefix is different. It's also common that different costs are reflected in the local number, like British numbers beginning 07 being mobile phones; it costs more to call one from a basic landline.
Does calling Bermuda cost the same as calling New York?