IMO, both sides are right here in different ways.
The crux of it is it's genuinely scary how much power modern infotech giants have over what information the majority of the public is exposed to, and that gives them historically unprecedented ability to bend the world in whatever direction they want.
None of the analogies brought up so far do justice to the scope of the issue, and pointing out that current legal definitions don't have a problem with it isn't any comfort.
We're already seeing these platforms leveraged to devastating effect against the political landscape, mainly due to the reckless disregard their developers had for any responsibility to the power their algorithms wielded in deciding what content users were exposed to for the purpose of keeping them around so there would be more opportunity to throw ads up on their screens. Stuff like the blacklisting of Alex Jones is a public facing maneuver to make it appear that they now understand that they wield this power and are going to try to exercise more responsibility.
But... uhh... if they didn't understand before the type of power they had in their hands, they do now after they've been raked over the coals for it. And from here they're going to begin developing sophistication in intentionally leveraging it in a way that doesn't set off any alarms in the public consciousness. If we don't make some noise about it now while it's topical, it will go the way of mass surveillance. It will become a ubiquitous feature of society that has deep effects on the nature of our culture and freedoms and makes everyone kinda uncomfortable, but has been so normalized for so long that most don't bother to think about it very much, except as an easy source of black humor. By the time we've reached that point, and it won't take long, it will already have become 100x more difficult to do anything about it.
It is a sticky problem. Because it's true that we don't want to establish a legal obligation for an organization to act as any individual's loudspeaker just because they have the technical capability. We want to defend notions of free association and so on. But all good ethical foundations can be broken and abused by context, which is why absolutism is bad. I'm not saying I have any answers. I just think that we do need to acknowledge the current state of information on the internet is in a dangerous place, and it's a new sort of situation that likely requires a completely innovative approach.
Maybe there is no answer, and our society is progressing in a way that requires us to just grow the fuck up in a general sense as a civilization and a species. Everything is so interconnected, complex, and powerful now, in ways that couldn't have been imagined 200 years ago. An individual's ability to abuse their freedoms to harm others continues to accelerate dramatically, but there's no point in restricting freedom to protect a life without freedom. If we want to continue pushing the scope and capabilities of our civilization to greater heights, we need to be sincerely dedicated to becoming better human beings in the process, or it simply will not work out in the end.