Their value also depends on how many USD's stored in that bank account (not transparent to ordinary people), and the inherent problem with USD - that the FED, a central authority prints it, remains still.

There are other - in my opinion more honest - crypto-only stablecoins, like Dai (of MakerDAO) or Augmint, which are not freezable by any authority, nor cheatable by bribed auditors. They are backed solely by crypto assets, all transparent.