The US is not unique in having free speech laws. And those laws aren't a complete free for all.
However, it seems to at least be a common belief that US free speech laws are often interpreted more broadly than free speech laws in several other countries. Moreover, compelled speech (as noted by the commenter) seems not unrelated here. For instance, see the somewhat recent Colorado web designer case [1].
[1] https://www.cpr.org/2023/06/30/supreme-court-303-creative-ca...