A lot of the complaints against 230 is that the sites are doing that too much, in ways that aren't to the liking of elected politicians, i.e. if twitter makes an anti-hate speech filter republicans say it's targeting conservatives, or if Facebook takes down an anti-fascism group democrats will say liberals are being targeted.
Forcing more legal liability on the major content hosting platforms won't make them go away, it will just make them into record labels or movie studios from the 1950s, where only an exclusive group of tightly controlled creatives get their mundane, uncontroversial content hosted. It's not going to create some cambrian explosion of alternative platforms - that already exists, and they don't get traffic because a one-stop shop for content is a natural monopoly.