Iron/Titan did not have any such high apy and still collapsed. In case of terra, I concur that the driving force was the Anchor ponzi, but it was the mechanism that failed.
Iron was explicitly under-collaterized, and it was also trying to lure stakers by providing yield-farming. DAI is the opposite, stakers pay the stability fee to open a vault.
It did have a yield-farming component (you could mint DAI at 1% fee and put it in the DSR that would pay 2%), but that got completely knocked out in 2020. That crash was already a quite expensive lesson (tens of millions USD) for the MakerDAO team, and a lot of the investors had accepted a haircut in order to bring DAI back to the peg.
To repeat: I am not saying that DAI is bullet-proof. What I am saying though is that all the reasons you are using to make your case do not apply to DAI as it currently works.
It did have a yield-farming component (you could mint DAI at 1% fee and put it in the DSR that would pay 2%), but that got completely knocked out in 2020. That crash was already a quite expensive lesson (tens of millions USD) for the MakerDAO team, and a lot of the investors had accepted a haircut in order to bring DAI back to the peg.
To repeat: I am not saying that DAI is bullet-proof. What I am saying though is that all the reasons you are using to make your case do not apply to DAI as it currently works.