There were a few products prior to MakerDAO that failed when their collateralized peg collapsed, most notably BitUSD and NuShares.
MakerDAO is somewhat more sophisticated and holds way more capital but the fundamental problem is that you can't exclusively collateralize a dollar peg from a highly volatile unit of account with elastic demand or black swan events can wipe it out.
MakerDAO is somewhat more sophisticated and holds way more capital but the fundamental problem is that you can't exclusively collateralize a dollar peg from a highly volatile unit of account with elastic demand or black swan events can wipe it out.