Let me tell you what happens in my neighborhood. I live in a subdivision a couple of miles out of town. Carloads, truckloads, and trailerloads of kids (most of whom were teens) are unloaded at the entrance of the subdivision to walk door to door with their pillow-case sized bags. At the door, sometimes you get the traditional "trick or treat" but often the child just stands there with the bag open. Again, sometimes a "thank you," but often they just turn and run on to the next home. No need to guess who it was, you wouldn't know them anyway. I was glad when the last of the candy was given away, and the front door light went out.
The whole drama of the exchange is gone. The meta-narrative of good and evil, power and surprise is missing, leaving the event crass and meaningless. Trick or treating is that mysterious time when children, with costumes, become something more than who they really are, curious strangers who have the ominous power to extract a ransom from you.
I can idealize a time when Trick or Treating was an enjoyable evening for a community. You didn't go to the store and buy bags of individually wrapped refined sugar, you made treats to give out. The neighborhood kids came around, often in family groups and you greeted people you knew, chuckled at their homemade costumes, and guessed who it was. The transparent threat of "treats or some trickery" was thwarted by sending them on with something good to eat.
Alas! My idealized version is just that, idealized. For me, however, I've decided that next year I'll just stick with the church carnivals with their "trunk or treats," and simply leave a twenty pound bag of candy on the front porch steps at home.