Ignoring the slavery factor altogether because xenophobe has that too, there is no point.
Before 2.2 they were one of the best ethics to choose for a strong economy, however now it's not so much. The stratofied economy lowers stability, which lowers resource production. Non fanatic workers get a 10% bonus that brings them to equal what it was before if looking at the starting game numbers, but specialists still take a hit to their production. You also end up having to waste a slot for a enforcer building on exceptionally worker heavy planets.
Fanatical authoritarian's 20% bonus is a little better, but every single other ethic gives better stuff.
The only way I can see a point in being authoritarian is if you turn off stratified economy to prevent the stability loss, after you conquer a alien race to enslave so the faction won't be unhappy. I haven't gone past 2250 as authoritarian yet but it feels like any other perk would be better. Give workers even less political power or make the worker 10%/20% bonus apply to all resource production.
Before 2.2 they were one of the best ethics to choose for a strong economy, however now it's not so much. The stratofied economy lowers stability, which lowers resource production. Non fanatic workers get a 10% bonus that brings them to equal what it was before if looking at the starting game numbers, but specialists still take a hit to their production. You also end up having to waste a slot for a enforcer building on exceptionally worker heavy planets.
Fanatical authoritarian's 20% bonus is a little better, but every single other ethic gives better stuff.
The only way I can see a point in being authoritarian is if you turn off stratified economy to prevent the stability loss, after you conquer a alien race to enslave so the faction won't be unhappy. I haven't gone past 2250 as authoritarian yet but it feels like any other perk would be better. Give workers even less political power or make the worker 10%/20% bonus apply to all resource production.