I am well aware that I am running against the stream. Mine is a small and largely unwanted voice. Still, someone needs to say these things, and the truth is that social media directly replaces natural subconscious functions. Or, perhaps more accurately, it displaces subconscious operations and acts in their place. And that is dangerous.

As we go through this, please understand that I'm not saying these things precisely, simply because no one knows how to say them precisely. Any "expert" on the subject could be attacked by half a dozen contrary experts, each with their own theory of the unconscious.

So, those who need to find fault may proceed as they must. I am doing my job all the same, because fear of the critic spawns self-censorship, and we very much need to address this.

What Social Media Does
I cannot affix a percentage to how much social media displaces our inborn subconscious minds, because no one knows how to measure such things. But that it does displace the human subconscious is easy to establish. Here, briefly, is some direct support:

Without a doubt, our subconscious minds filter our sensory inputs, delivering only a fraction of them to our conscious minds. Also without a doubt, social media does the same thing: Sifting through all the inputs in its system (which double, counteract or displace a large number of our own sensory inputs) and delivering to its user those inputs which serve the system's needs.
Our subconscious minds search our internal data banks for relevant memories. Social media does the same thing, again displacing human operations. (While monetizing them.)
Our subconscious minds trigger involuntary reactions like disgust, outrage and revulsion. Social media hijacks this process and pulls such reactions out of its users, rather than allowing them to form naturally.

Our subconscious minds recognize and process impressions of status. Advertising has long monetized this, but social media monitors the user's reactions and triggers them very precisely, accelerating and directing the process.

Social media corporations have employed and do employ a large number of professionals, precisely to develop routines to increase "user engagement" (aka, addiction), thus increasing their profits. More or less all of this involves subconscious vulnerabilities. If not, these companies would simply reason with their users, convincing them to engage more. If you're trying to make people do something, and if you're not openly convincing them, you're left with hijacking their instincts, which means their subconscious operations.