There is no such thing as "emotional addiction" or "physical addiction". There is addiction, and some substances have withdrawal symptoms when discontinued.

I’ve been curious about what are people experiencing when microdosing it?

My understanding is that - nothing, there’s no perceivable difference.

If this is the case, what is the addiction to?

> what is the addiction to?

Perhaps psychological addiction to the habit? Fear, anxiety, uncertainty about what might happen if you stop the habit?

As is the case when someone discontinues SSRIs.