What mostly gets banned at big social media sites is spam and bots. The political speech that does get banned is overwhelmingly violent.
The right gets banned more because there is no liberal equivalent of the Christchurch shooter, the Buffalo shooter, the El Paso shooter, the Charleston shooter, the Tree of Life shooter.
The last president got kicked from Twitter because he tried to violently overthrow our government.
Kiwifarms was finally taken down by cloudflare only because of immediate threats of violence.
The right wing in the US has a violence problem. Culture war junk and social media moderation policies pale in comparison to this problem.