Vulnerabilities CAN be avoided, including in software you write yourself, by reducing the attack surface introduced by dangerous, superfluous, given-by-default https://en.wikipedia.org/wiki/Ambient_authority by insisting on the usage of operating systems, virtual machines and programming languages that use https://en.wikipedia.org/wiki/Capability-based_security and allow programmers to apply the https://en.wikipedia.org/wiki/Principle_of_least_privilege easily, correctly and on a, if desired, ever finer-grained level.

People figured this out 50 years ago but the rest of the world prefers to suffer I guess https://github.com/void4/notes/issues/41 https://en.wikipedia.org/wiki/E_(programming_language)

I don't trust myself to do many things correctly.

Even then you are depending on the integrity of your development environment (see: Ken Thompson's compiler hack).

And the libraries, and the language, and the platform, and the hardware it runs on. It's blind trust all the way down.