I liked how abnormal reedus on Blue Sky described the misery in choosing facism.

sometimes i think about that thing a disco elysium dev said in response to someone asking why choosing fascist options lowers your morale. that being a fascist is miserable, since it requires you to believe that you are being dominated by the weak and unworthy in everything you do.

He'd misremembered this Reddit comment:

Being a fascist is a deeply demoralizing experience. You have to not only radically alter your worldview to make reality fit into your unhinged schema, but that worldview is predicated on the notion that the weakest, most unworthy degenerate worms on the planet are somehow overpowering and humiliating you on a moment-by-moment basis.

In mechanical terms too, the lowered morale also reduces your volition score—the more you indulge in your delusions, the less you are able to exercise self-control and self-awareness.

The point of fascism being mechanically detrimental—the ludonarrative theme—is that fascism is an unequivocally self-destructive ideology, the practice of which only serves to nurture that self-destructive urge and turn it outward. It's not like Dark Side points in KotOR where you can access cool new abilities and get to enjoy being such a nasty lil rascal; you are not supposed to enjoy being a fascist in Disco Elysium. Fascism is the act of self-deception in service of making your own life more painful, solely for the payoff of making life more painful for people you dislike.