And harmful items are frequently censored - from basic rating systems to the prevent of child pornography: Society and governments censor things that cause harm. The parent comment calls out germany specifically, yet this is a country where nazi symbols and gestures are censored (with a well established rationale for doing so.)
Covid disinformation is undeniably harmful and contributes absolutely nothing. Social media networks choosing to pull down harmful misinformation is entirely consistent with not only how they operate but how society operates as a whole.