What do they provide in phone service that Google Voice doesn't already do for free? Google will give you a local number and forward it to specific phones for free, and I don't see why someone would use a paid service over that.
It's often quite a bit of work for us to get numbers in the exact area needed for a particular prison. It's certainly not always as easy as picking out a random VoIP provider and picking a rate center.
And I don't know if they did develop their own system or are wrapping an existing VOIP solution, I didn't see it mentioned specifically.
If a new site opened up that offered exactly what Reddit does, but wrote their own code from scratch, (and charged), I would also ask what they're bringing to the table over Reddit, what features they have that reddit doesn't, and would criticise them for not reusing old code that did what they wanted if they couldn't show me any better features.
It is definitely not a new idea to reuse existing ideas, even if you don't reuse existing code, to provide previously unserved/underserved markets with already existing services/products, nor is it a new idea to charge for it. I honestly don't know what you're getting at. Do you think they should provide this service for free because others do? Should customers just be smarter and know that Google Voice exists? What exactly do you find is wrong about this situation?
Who said they aren't piggybacking on GV (or somebody else)? They were vague about the tech behind their VOIP. Which is what I would expect from somebody doing exactly what you suggested. They wouldn't be honest about that or they'd be telling their customers they could just use GV instead...
What they've done is found a market and figured out how to market to them. That's huge. If you can solve those problems, you could do it too. Not every business has to make a huge technological leap to be successful.
GV numbers are generally blocked by the pay phone providers and the FCC has allowed that.