Phrases like "shall make no law," "shall not be infringed," etc. seem to imply the rights are absolute. Why is this not how SCOTUS has interpreted the Constitution?
Because people inevitably come into conflict exercising different aspects of their rights. For example, the 1st amendment says that congress shall make no law abridging the freedom of speech. Someone who runs a sound truck around a residential neighborhood at 3am extolling the candidate of their choice would be exercising their right of free speech but it would be a significant negative impact on all the folks in that neighborhood trying to sleep. Governments and the courts have to balance the free speech rights of the person running the sound truck versus the rights of other citizens to go about their lives.
In this case the compromise is that cities and states can pass noise ordinances that restrict the hours when amplified sound systems can be used, but such restrictions have to be content neutral.