Firstly, let’s distinguish between failed and failure. If a project doesn’t achieve the desired result - we could say that it failed, whereas if we believe that it hasn’t gone well and nothing could be improved, then it’s a failure. ‘Failure’ doesn’t leave much room for hope; it sounds so terminal. So let’s consider the alternative - never failing.
Imagine progressing through your whole career one step at a time; always getting promoted; always increasing your salary and nothing ever going wrong. It’s certainly comfortable, which can be pleasant. However, would you feel that you have been challenged enough? And would that be satisfying?
How would you know when you had reached your full potential? Maybe you would feel like you had reached the top, but you wouldn’t know. That’s why I believe failing is crucial; you know when you've reached full potential because you can't go any further.
There could always be a higher rung on the ladder that you never got to because you were too afraid that you’d fail. Then you could only look back and ask what might have been.
It’s often said that the people who fail the most also succeed the most, which is not hard to understand; especially if they are continually learning from the failures.