Why does this require to blow fuses? Just store a secret into the CPU that can only be unset if the same secret is provided again. It could be totally reversibl

Why does this require to blow fuses? Just store a secret into the CPU that can only be unset if the same secret is provided again. It could be totally reversible, as long as you know the secret, that way the lock could be removed when decommissioning the system. With a tiny bit more fancy crypto one could also generate per-system unlock keys so that a vendor doesn't have to reveal his master lock or something like that. Unlocking bootloaders is a solved problem on android. Why introduce a worse solution that creates vendor lock-in?