Indemnity is an advantage conveyed by the State. The State ought not provide the advantage to some speech at the expense of other speech.
This still seems to be point-of-view neutrality on the government's part: an anti-fooist site that removes fooist comments gets the same immunity as a fooist site that removes anti-fooist comments (or a neutral site that removes neither). Is your view that it's wrong for the government to, in a sense, help the fooist site in the first place even though it's equally willing to help the anti-fooist site in the same way? Does that mean that there shouldn't ever be a subsidy for "newspapers" (open to any newspaper regardless of its editorial line or policies), but only for "neutral newspapers" (that don't editorialize)?
If a website can curate what is said so that it is visibly filled with defamatory material about a specific target, the organization curating the material maintains complete immunity from what would otherwise destroy a newspaper or any other organization that is actually liable for what is printed in it.
I don't think this should be possible for any organization, regardless of who they are. This immunity should require an extreme impartiality on behalf of the website. It's meant to protect organizations from speech they don't control -- when they assert any control over that speech, it's now their speech.
IOW, the message can be crafted by the platform even if the words are provided by the users.
Platforms may or may not be slanted people can pick a different platform if they don't like their current ones slant or make their own. People ought to have no right to have a platform to be neutral in what communication they facilitate between their users and any attempt to enforce that is inevitably going to devolve into being slanted towards those with the juice to hire the lawyers to suppress speech.
Just as an article made of quotes would.
And if the message in the feed/article is libelous, it's shameful (though perhaps legal) to hide beyond the argument "I was only quoting other people."