On the contrary, every plane that takes off does so despite the known chance that it could crash.
There is no component of any machine that is 100% guaranteed to not fail under any circumstances. What the bloody hell are you talking about?
> If a component may fail
As has already been pointed out to you, all components may fail, including any that you add to compensate for the potential failure of other components.
An engineer should know this by instinct.
Adding redundancy was incorrect. Redundancy should be inherent to the design. If one must be added, the design is already a failure.
Redundancy does not mean adding a new component, but maintaining operation under component failure. For example, if the engines fail, it should still be possible to make a controlled landing.
Cf. The grounding of all Boeing 787s: https://en.m.wikipedia.org/wiki/Boeing_787_Dreamliner_batter...
One in 1.2 million flights crash. This is literally a "known chance".
Planes take off anyway.
Crashes are anaomolus events that happen for very specific reasons. Reasons that do not have any seeming connection to any other crash. I don't see how a retrospective could predict anything about the success of future flights.