Take Congress for example. Approval ratings are what, 20%? They're generally seen to be corrupt, and they don't get anything done, right? So why aren't they voted out of office? Why are people surprised when they end up having low morals or corrupt? If people honestly cared, wouldn't they immediately demand change? But the status quo remains.
So either the people have no power to change things, or they collectively forget these things every day, or the real reason: they don't really care that much, but like to seem like they do.
Because the average approval rating of individual members of Congress in their own district (for the House) or state (for the Senate) is much higher. For most people, it's (some large subset of) the 532 members of the Congress that they don't get to vote for that are the problem.
For your congress problem it’s actually none of the reasons you listed. The cause of the discrepancy is the 20% approval rating is for congress as a whole, but people don’t vote for congress as a whole, they vote for individual representatives.
People do like their own representatives, and those approval ratings are
often very good in their own district. It’s the rest of congress they don’t like.