> I always thought laws would get more just with perfect enforcement
As Edward Snowden once argued in an AMA on Reddit, a zero crime rate is undesirable for democratic society because it very likely implies that it's impossible to evade law enforcement. The latter, however, means that people won't be able to do much if the laws ever become tyrannic, e.g. due to a change in power. In other words, in a well-functioning democratic society it must always be possible (in principle) to commit a crime and get away.
The people should always have the opportunity and power to behead the government.
Yep, not ever being able to break a law means that whatever the current set of laws are will never be able to be changed. If people can't ever push the boundaries of the law, we can never realize that the boundaries are in the wrong place.
Take some examples of laws that have changed over time. Say, interracial marriage. It was illegal in many places to marry someone of a different race. If this had been perfectly enforced, no one would have ever dated or see couples of different races, and people would have had a lot harder of a time exploring and realizing that the law was wrong.
The same thing could be said about marijuana legalization. If enforcement was perfect, no one would have ever tried marijuana, and there would have never been a movement to legalize by people who used it and decided it was not something that should be banned.
We need to be able to push boundaries so they can move when needed.