If all the people who care about a problem leave, it becomes harder for the organisation to solve the problem. This is one form of organisational rot.
Most of us are good at one and bad at the other. Eg, my instinctive response has been to quit my job when I’m not enjoying it. And that’s fine, but some of the situations were almost certainly salvageable. And I could have helped. Some people try to fix a workplace indefinitely, even to their own detriment, and even when the situation is probably impossible to fix and they should just get out of there.
I think it’s really important to learn both skills. And remind myself when I’m stressed that they’re both options.