I feel like whenever S230 comes up and I see people defending it I get confused because the defense doesn't seem to address what seems to be the concern of the people saying it needs removing (or more realistically reforming).

The concerned is one of consistency in how media is regulated. E.g. Facebook, is the worlds largest media company, and it truly acts and behaves as a publisher now. It acquires its content from an army of paid and unpaid providers. They may be individuals, often they are influencers, often they may be nefarious agents and companies. It then decides how to place that content in it's "publication", which just happens to be an app and website. It goes out and tells the market, "I have this great publication in which you can place ads!". It then sells ads to those people, and makes a decision on how to place those advertisements inside its publication alongside that content that it acquired.

So how is it not a publisher? And why should it be regulated to any kind of different standard from other publishers?

You beat me to it.

I'd emphasize that the scummiest sites with zero moderation never needed Section 230! Section 230 is what allows you to have some moderation (e.g. banning spammers) without suddenly becoming entirely liable for anything that passes the filter.

Blindly reverting Section 230 means eliminating that moderate position, splintering sites into:

1. Ones that abandon moderation entirely in favor of chaos. Maybe you can salvage something by giving opt-in filtering tools to individuals, but you'll still have the problem of someone using your site to store ten terabytes of the Bee Movie.

2. Ones that demand participants sign a serious legal document promising to pay for any problems before they can submit anything.

3. Ones which remove almost all expressive ability, beyond narrow things like like/upvote features.

Paid advertisements should be exempt from Section 230.

If you're earning almost 200 billion dollars a year directly from the posting of a certain type of content, you can afford basic moderation to avoid obvious scams and fraud.