This is a good observation, but I don't think it absolves social media. There are likely many factors increasing polarization, and social media may amplify those factors and/or turn otherwise harmless factors into harmful ones.
The core idea behind social media is that it amplifies various voices, instead of those few who's job it is to participate in the media. In the US, this has effectively turned our right to freedom of speech into a right of freedom to broadcast.
The total size, wealth, and political influence of the US are much larger than the most culturally comparable nations. The value for those within and without the nation to spend effort using social media to influence discourse and election results is high, and is likely at least a partial factor.
The core idea behind social media is that it amplifies various voices, instead of those few who's job it is to participate in the media. In the US, this has effectively turned our right to freedom of speech into a right of freedom to broadcast.
The total size, wealth, and political influence of the US are much larger than the most culturally comparable nations. The value for those within and without the nation to spend effort using social media to influence discourse and election results is high, and is likely at least a partial factor.