That's not what "vulnerabilities are solvable problems" means, except maybe for cybersecurity maximalists who believe that, "bro, add passkeys, and just one more thing, attestation, and W^X, and ..., and there will never be vulnerabilities".

Vulnerabilities will always exist. Systems will always be hackable. You solve the problem by patching what you can, and cleaning up after what gets exploited, if and when it gets exploited.