The difference is that you can always redeem UST for LUNA, which directly results in minting additional LUNA (the total amount of LUNA in circulation increases when UST is destroyed), while the same does not happen for debt-based stablecoins.
In the case of DAI and other debt-based stablecoins, there is no minting of additional collateral when liquidations occur or when debt is repaid (the total amount of the underlying collateral in circulation does not increase when DAI is destroyed).
This is the main difference between so-called "algorithmic stablecoins" (e.g. UST, FRAX, USDN), which rely on internal collateral (whose supply can be arbitrarily expanded/contracted by the controlling entity) and "overcollateralized debt-based stablecoins", which usually rely on external collateral (whose supply cannot be arbitrarily expanded/contracted).
Treating these two different things as if they are the same is not particularly insightful.
In the case of DAI and other debt-based stablecoins, there is no minting of additional collateral when liquidations occur or when debt is repaid (the total amount of the underlying collateral in circulation does not increase when DAI is destroyed).
This is the main difference between so-called "algorithmic stablecoins" (e.g. UST, FRAX, USDN), which rely on internal collateral (whose supply can be arbitrarily expanded/contracted by the controlling entity) and "overcollateralized debt-based stablecoins", which usually rely on external collateral (whose supply cannot be arbitrarily expanded/contracted).
Treating these two different things as if they are the same is not particularly insightful.