As I have long thought, the ONLY secure computer system is one that is turned off, disconnected from any network, disassembled into its component parts, and then reduced to atomic dust. Even then the atomic dust could be reconstituted into a computer and become infected. Hence, the only really secure computer is one that remains as atomic dust. Unfortunately, such a computer is not very useful but it IS secure.
I suspect there will always be a trade off between security and utility. Isn't that the way nearly everything is? After all, even being alive is ultimately fatal. No one gets out of life alive. So accept reality, accept the risks, make the best of it, and get on with living and computing. Entropy will win in the end but have fun fighting it as long as you can. That fight is as good as it gets.