You're kidding me, right?
How could it possibly suck to be an SJ? Any sane person would be jealous of them!
If I were an SJ, I could probably actually get things done, and not have to worry about all this... nonsense all the time.
I mean, think about it. Society is set up in a way that is more tailored to SJs than any other type. Also, when you find comfort in conformity, you can lead a much more relaxed life than if you feel a spirit of rebellion over certain things. When you're willing to obey an authority figure and not take risks... to just keep the peace. Without feeling guilty, but actually feeling like you're doing the right thing.
I envy SJs, because they can be content with very simple lives, and most of them find happiness easily. Being an NF, means I'm constantly vexed with questions that cannot be answered to my satisfaction. I'm constantly worried about how things are developing, what things really mean, whether or not my assumptions are right.
If anything, I bet being an SJ probably sucks far less than being an NF. Especially an NF who cares so much what other people think, that they often try to look like an SJ outwardly, but hide quite a bit of existential angst and uncertainty within, and always feel conflicted as a result