Pre-2008, MBS were accepted as repo collateral at haircuts that assumed the underlying was liquid, diversified, and uncorrelated with broad stress. When that assumption broke, the haircut problem became a solvency problem almost overnight.
DeFi just ran the same play with LRTs.
Aave's contracts didn't break. Their risk perimeter did. One bridged LRT, 93% LTV, no velocity limits, shared liquidity pools, and a tail risk that everyone priced as negligible until it wasn't.
Different instrument. Same failure.
Same lesson nobody wanted to learn until it was expensive.