And you can take advantage of their network effects by implementing a POSSE system. Publish on your own site, syndicate elsewhere. That way, your website is the source of truth and the other places are like museums you curate to.

Why should you go thru the trouble? Because these social networks own your content and your audience and won't hesitate a second to drop you if they deem fit.

For the majority of people it's the opposite of utility. Not even inutility or uselessness, it's negatively useful.

In any social network where "network effects" are a thing in the first place, there is more content produced than can be consumed by a particular user. The algorithm (tm) is forced to curate certain pieces of content out of circulation and can only heavily promote a negligible minority of content. This creates content reach distribution that is essentially a parabola. While there can be tons of signals to adjust the reach, the primary signals are inevitably going to be virality of the account and early engagement. You can't reasonably look at long term engagement due to content to eyeball ratio.

Ergo, posts must be designed to quickly grab early attention in an infinite feedback loop and this incentivizes cartels and bot farms to create echo chambers. Both extremely harmful phenomena.

I'm not sure I'd describe cartel behavior as utility.