I guess Kevin Smith is irrelevant.
But, as the Dark Knight pointed out "you either die a hero or live long enough to see yourself become the villain." I guess Smith live long enough.
Chasing Amy was always my favorite, but Clerks and Mall Rats were classics, Clerks II was pretty hysterical, Dogma (especially if you are Catholic like me) is absolutely cutting and brilliantly so. Jay and Silent Bob... to much of the side characters, but at the end of the day they all had something in common...
... they all cut into fandoms in only the way that fans, legit come to the comic book store every Wednesday, know what Diamond Distribution is fans of geek fandoms can completely and hysterically criticize the things they love.
He even cut into the original Star Wars. It was Geek Counter Culture and we loved every minute of it.
Clerks III has NONE OF THAT. Smith used to criticize pop culture, and now that he's part of it, his scripts don't work. They lost their edge. The brilliance of his early work has faded to the land of sell outs.
Now you are more likely to see him weep over a bad Star Wars movie in an obvious shill than you are to see him make jokes about how many innocent construction workers died in the second Death Star.
And when he stopped being able to take apart fandom's and playfully make jabs at them, when he stopped criticizing pop culture and started to shill for it, he became irrelevant.
There is no need to watch Clerks III, everything that made the first two... that made most of his early work great is absent in this on.