Assuming social networks are common carriers means also assuming that laws and law enforcement would need to adapt to the resulting spam filled environment. People would also need to adjust the way they communicate online, you'd need to create something similar to google plus circles to allow free and open discussion that is self moderated. You'd need new forms of trust protocols. You'd need...
Most people just can't fathom how much would need to change to make the internet work. They try to fit in what we have now and just say well that won't work so you're wrong.
I've noticed people also struggle with the big tech censorship argument. The amount of times I've said, censorship laws should extend to social networks and been met with "censorship only applies to government" arguments as if that wasn't the exact premise my argument started with just boggles the mind. Yes, I know, they're private companies, I'm advocating for changing laws so they do apply, not applying laws that don't apply.
This is explicitly where Musk has stated he wants to take Twitter.
For instance, I HATE that people will quote people I've blocked, and I see their comment with a greyed-out quote box. I want blocking to work like Facebook. If you block someone there, you see NOTHING from them. I don't want to even see tweets that REFERENCE something they said. Twitter currently "eggs you on" with this dark pattern.
If we could tailor our own, personal "algorithm," the end result will be something like the proverbial "street corner." Any idiot can carry a sign and shout at people, but YOU can decide if you want to walk up and hear him, duck your head and pass by, or take another street, and NOT have Twitter make that decision FOR you. In my mind, this could be a very different scenario than what we have today.
Another obvious retort is that people saying as such are laboring under the delusion that the Freedom of Speech is a right granted under the First Amendment, rather than being a natural right which the first amendment states is outside the purvue of Congress to regulate... which leads us back to the original retort above.
Ultimately, though, people who make such arguments aren't actually interested in an argument. They're simply making up excuses for their class bias so they can go on oppressing the proletariat without having to just openly state that as a self-identified member of the petit bourgeoisie they align with the interest of the bourgeoisie and don't care what happens to you or I... since openly admitting that wouldn't allow them to go on larping as heroes of the revolution (or however they phrase it in the cosmic gag reel running in their head).
https://www.nbcnews.com/think/amp/ncna1245308
https://www.quora.com/Why-is-Twitter-censoring-liberals
https://www.politico.com/amp/news/2020/10/26/censorship-cons...
.... that censors them. Key word.
> This idea that the left loves social media companies is a right wing narrative
You don't have to be right wing to observe leftists embracing censorship of anyone who opposes them.