If these platforms presented the content without interpreting and curating it for profit, they could at least take the stronger stance of being a platform instead of a speech curation/distribution/amplification system.
For example if Signal was externally pressured to take down speech based on its content, they would be like "We don't have that ability." But in the case of Twitter and FB, that ability and practice is at the very core of their business model.
The problem, IMO, is that most users don’t understand how social media works from a business perspective. Advertising companies put a lot of effort into not being known as advertising companies.
Another fun thought experiment: consider who runs political ads, especially local advertisers (highway billboards etc) and what speech they’re willing to accept. Consider Comcast / cable networks and what speech they’re willing to accept. Who are their customers, how are they making money, and how does that affect what speech they are willing to accept on their platforms.
That says a great deal doesn’t it? They are too ashamed and know it is an immoral business.
Do you think that if we somehow broke this monetization model, that companies like Twitter, Facebook and Google would cease to be the behemoths they are, and the amplification mechanism might go away?