"They" feels kinda plural. There's "it" but that's objective.
And we don't have a plural "you", which is one of the first things slang fixes: "youse guys", "y'all"
I swear to god, his run from 140 to 150 includes some all-time bangers. Delicious Cycle. The parodies. Carebearstare. Mispronouncing. (I still say Blag.) Sudo make me a sandwich. Grownups in the ball pit. I love all of xkcd, but that's peak xkcd.