That's because you are buying into western propaganda. These countries operate on some kind of "hype" of law. The odds that you'll go to jail in Singapore for committing a "punishable" offense is really low. I was surprised how lax Singapore is given its reputation. It seems that they are holding the status quo by that reputation rather than the enforcement of it.

This is the same for many other countries but not the case for the US. Also your first two examples applies to really small list of countries (Iran and S.A.) and their current governments are the disgrace of the world and are not really an example to take (like going too extreme and something the US shouldn't "I guess" be compared too).