Even absent a comment section, most blogs are hosted by someone else (e.g. WordPress), who does not vet the content on that blog. That won't be possible anymore in a post-Section 230 world.
No problem, you say, I'll self-host my content on AWS and use CloudFlare as a CDN. But AWS and CF also have no section 230 protections any more either and probably won't do business with you unless you indemnify under some kind of insurance policy (which you won't be able to afford as a small blog).
Even if you run your own server and install it at home, the lack of section 230 protections will probably make your ISP responsible for content you publish (remember: your ISP is not a common carrier - thanks FCC) so you're probably going to find that all consumer ISPs are going to have terms of service that prohibit publication, and technical implementations that enforce that.
I mean, in the non-Internet world, if I want to make a newsletter and mail it out to a subscriber list; I can at least do that. All I need is a laser printer, and a stack of stamped envelopes. The postal service is a common carrier, at least.
Today's internet is a composition of platforms, all of which are really only possible due to the existence of section 230. It blows my mind that people are so blasé about the idea of tossing it out or reworking it in a naive way.