You’re right about attackers being able to change runtime code.
pnpm does have some other features to prevent supply chain attacks, so there is still something to learn from other ecosystems. For example pnpm has a cooldown period for new dependencies and can prevent trust policy downgrades (eg new version published without build provenance where older versions did have it). See https://pnpm.io/supply-chain-security
pnpm does have some other features to prevent supply chain attacks, so there is still something to learn from other ecosystems. For example pnpm has a cooldown period for new dependencies and can prevent trust policy downgrades (eg new version published without build provenance where older versions did have it). See https://pnpm.io/supply-chain-security