Thanks to Spacekaren for explicitly confirming what I wrote (in Italian)
The objective function of Twitter (as of any social) is to maximize user retention so as to create opportunities to show them advertisements. (Twitter [was] a little less than others, to be honest).
This is achieved by fostering and stimulating emotions to increase virality and engagement. Emotions that often end up being exacerbated tensions, increasing the polarization of people (and with them, societies).
Mastodon is designed to achieve the opposite effect. This is why Mastodon’s creators have included or excluded certain features, with the purpose of creating friction, of slowing things down, to reduce virality, to inhibit waves of emotion, not to stimulate it.