Custody vs discretion is a real distinction but the reason vault trust is so contested is downstream of what happens at liquidation. A discretionary curator is scary bc when a market goes bad, exit depends on external liquidators, oracles, and someone unwinding into a fire sale.
My two cents on this debate is that custody and discretion are two different dimensions and should not be conflated.
Custody is about who holds the keys and therefore assets
Discretion is about who makes the investment calls on assets. Examples:
1. Custodial & non discretionary: Coinbase spot account where you decide on your own investments
2. Custodial & discretionary: hedge fund/mutual fund
3. Noncustodial & non-discretionary: self directed defi like swapping on Uniswap
4. Noncustodial & discretionary: managed onchain vault
You can give up one without giving up the other.
Much of DeFi is noncustodial because you own the keys and the assets. But the meat of the debate really is around what should be considered discretionary or not.
Vaults that are more programmatic in nature with user ability to veto any decisions would be closer to the non discretionary end to my mind vs designs where users don’t have control over subsequent decisions that are made to the product evolution