The 1A jurisprudence, to my understanding, basically results in the courts virtually never finding that the government has a legitimate, competing interest in limiting political speech.

But courts are willing to find that certain speech that is apolitical can be limited (the previous "fire in a crowded theatre" example). Basically the courts have recognized 1A established freedom of speech to protect political dissent and political ideas. Porn, for example, has limitations that would never apply to political ideas.

Again, the fire in a crowded theater example was actually political, and the decision was overturned. It no longer stands as precedent.

Limitations on porn still exist in a few areas, but they are gradually being rolled back—obscenity laws were once widespread and highly restrictive. Most still standing carveouts are pretzel twists that probably need to be corrected with a clarifying amendment; they are on very shaky ground.

The court has recognized speech protections outside of politics many times, including protections for authors and creators who were not explicitly aiming for political statements. For example, Brown v. Entertainment Merchants Association established that video games are protected expressive speech, even if they are violent trash that aren’t attempting any political point whatsoever.