The basic idea seems sound: people want to transfer around cryptocurrencies (or speculate on them, fine), but actually selling them for USD is somewhat hard and peppered with regulatory issues. So swoop in with a partial solution: a stablecoin worth exactly 1$ USD that you can transfer quickly around using the blockchain, but doesn't have any price volatility so is a safe store of value until you can move out and redeem for USD through a slower, regulated offramp (of which there are fewer).
That seems like the hard part? They solved all the hard problems, and it's so useful that it should be possible to get rich just by charging small transaction fees, success just requires doing all that plus not being crooked and lying about the 1:1 backing.