The problem is that it's very hard to get the balance right, because the same tools that you can use to regulate harmful speech can be used to regulate undesired speech.

Again, you dismiss the concerns of "potential for abuse", but how about you dismiss them by accounting for pretty much everything China does, the apparent heavy intervention by Twitter into political matters on behalf of the Democrats, the U.S. dictating to news organizations what they could and couldn't cover especially pre-Vietnam-war-protest era, and so on?

This isn't exactly an abstract boogeyman. It comes up over and over and over and over.

You mention Elon abusing his power. I'm not sure what, specifically, you're referring to? But anyway, how is that not an example that we should be more worried rather than less?

Corporate social responsibility missions are, all else being equal, a nice thing to have. But my main concern is that it's just not a big enough tool for the job. If we're very worried about harm, it's not enough. If we think, okay, there are some harms, and somewhat less would be good--then sure. If we're very worried about abuse of power, it's not enough. If we think, okay, power is abused a little bit, and somewhat less would be good--yes, sure.

For instance, oil and gas companies have had CSR missions for a while. Heck, Chevron has been advertising its CSR for decades with its "People Do" line of ads. But it's not legally binding (https://www.forbes.com/sites/uhenergy/2019/10/11/can-corporate-social-responsibility-be-legally-enforced), and even if Chevron was sliiightly less bad than, say, ExxonMobil, it's hardly turning the petrochemical companies into paragons of world virtue.

You say "Look at how Elon is abusing his." (Power, I'm assuming?) Well, if so...then...doesn't this argue more for something that is actually binding?

And you can't just say, "But, harm!" in favor of moderation without addressing "But, harm!" in the case of e.g. China. I think the United States has a pretty good historical record, but this is mostly mandated by the First Amendment. It didn't happen organically: it's both legally mandated, and fostered by culture that is consistent with that legal mandate.