You are only thinking of attacking computer directly itself. Often people socially engineer access to a computer system. Many UK super markets were hacked, using some of the software that is very secure, because people managed to socially engineer access.
There is nothing and I mean nothing that is completely secure.
> There is nothing and I mean nothing that is completely secure.
You're not wrong, but dismissing security because there are always other threats is just security nihilism. See my link.