Frieren does traffic so heavily in fascist tropes
It quite literally does the exact opposite, repeatedly and emphatically devaluing everything Fascists value and making its villains just do literally every Fascist thing. Its only misstep is in making a species of ontologically-fascist demons who just can't help but do fascist things. If Frieren were fascist it would be oriented around fascist ideals instead of just stumbling into a problematic analogue to one facet of real-world fascist propaganda by making its might-makes-right, anti-empathic, elitist, warrior-cult, racial-supremacist villains innately fascist by dint of being magical predators, instead of making them simply indoctrinated into that ethos or the like.
This is even more tiring than the Dandadan struggle sessions.