Inaction vs. failing, which is worse? Easy, inaction, hands down it the most detrimental thing we can do to ourselves. Failing at least is still progress/forward movement.
Failure has a negative connotation to it, an undeserving one at that. Failure is not the end of the line, it is part of the process on the road to victory. Failure helps us build our mental and emotional endurance which aids in our long-term success. Emotional endurance helps us grow to the next level. No emotional endurance means no failure was overcome and subsequently no growth took place.
A muscle performs better when it is pushed to its limits. It is when the muscle breaks down through wear that it rebuilds and strengthens. And like the body, the mind and our emotions follow suit as well.