However the government does allow political signage in public places and has laws preventing others from removing them. However if said signage is considered by the local government to be inappropriate then it is removed. So how is a social media platform different than that public arena?
The problem I've seen is that places like Facebook and Twitter have moderation that is clearly biased. The Hunter Biden laptop story is a perfect example...they restricted the sharing of the NYP story despite no evidence that the article had any misinformation in it (still a factual story). This is no different than if you had political signage on your property and the government built a wall right outside your property to block anyone from seeing it. Are they restricting your 1A rights...technically no, but realistically yes.