A transtor is a semi conductor. It moves electrons through a semipermeable barrier. This is an interaction at a quantum level. The smaller you make them the more prone to quantum tunneling they become. So no a transistor is not on or off, 0.001% of the time it's both or neither.

There are safeguards in place in computers to check for random bit flips because it is needed. It's called hashing.

Im not saying computers don't work. I'm saying a computer is a machine that processes information on a quantum level. And it is impossible to separate the computer from it's quantum interactions. Heisenbergs uncertainty principle applies wether you want it or not.

You cannot build a house without bricks.