Not necessarely, my 24th century authoritarian xenophobe slaver empire was the most powerful empire on galaxy, with huge fleets, supported with huge industries pumping alloys and consumer goods.
What applies in 24th century can apply well in 20th century.
Stellaris also basically, or rather
almost completely, lacks the internal simulation that is so crucial to Vicky 3. Of course there aren't any Jacobin rebels in your fantasy universe, the game can barely handle the pops as they are now. Adding the internal instability systems Vicky has would melt your CPU.
Also, Stellaris a science-fantasy game purpose-built to allow you to play as schlocky b-grade sci-fi and sci-fa empires, one of which is a futuristic empire that is incredibly advanced yet inexplicably still relies on manual labor. So of course it has mechanisms to allow for that.
That shit won't fly in Victoria, since it's far more about historical simulation and it actually has mechanics to screw you over if you carelessly go for the absolute monarchy route,
particularly when combined with the attitude of "My people are the best and everyone else can screw off" and "Why have peasants when you can have slaves". Better hope your military doesn't turn coat over to the Jacobin side.