It seems to me that any decentralized stablecoin would break the impossible trinity. [0]
Basically, since the interest rate is fixed (at 0 in this case, I believe), there's an incentive to sell DAI in favour of some higher-yielding currency, which creates a downward pressure on the price. So short of preventing DAI from being sold somehow, in order to maintain a peg, someone needs to pump money into DAI at a loss.
You can try to build a complicated system to hide all that, but it seems the goal of a stable peg is simply impossible. Even for nation states it is only possible in the case they have sufficient resources and the will to maintain a peg.
Basically, since the interest rate is fixed (at 0 in this case, I believe), there's an incentive to sell DAI in favour of some higher-yielding currency, which creates a downward pressure on the price. So short of preventing DAI from being sold somehow, in order to maintain a peg, someone needs to pump money into DAI at a loss.
You can try to build a complicated system to hide all that, but it seems the goal of a stable peg is simply impossible. Even for nation states it is only possible in the case they have sufficient resources and the will to maintain a peg.
[0]:https://en.wikipedia.org/wiki/Impossible_trinity