I get what you are saying, but consider this for a moment....
yes things fail in a cockpit, but 99% of the technology in a cockpit is only there to interface with a human,
dials, gauges, switches, screens, control sticks, pedals.
all that stuff is the stuff that fails. If you took all that stuff out of a plane the reliability would sky rocket.
You can get all of the technology including sensors required to fly a commercial airliner on a circuit board the size of a small laptop.
So if you take out all that interface technology and say replace it with 10 parallel autopilots and additional redundancy on everything.
That has to be more reliable than all the switches, dials and human interface technology that is constantly failing today.
How many times have you been delayed on a flight due to a 'failed gauge' that needs replacing.
Imagine just getting rid of all that stuff and having standardized sensor packs that can be massively parallel and redundant.
Stuff would just not fail any more, not catastrophically anyway, and if it does, the aircraft would just ignore the output from that sensor pack because it didn't correlate with the information coming out of the other 9.
The only reason aircraft are unreliable is because we have to fill them up with technology so the pilots can see what is going on, just get rid of it all and the problem will go away.