Christmas so far outranks Halloween in consumer spending, I can't imagine anyone worrying much about the paltry 10B we will spend in 2021 on Halloween. Christmas will be 100x bigger.
People buy a lot of stuff during Christmas, but they get used.
EDIT: I think so.
We let our kids wear their costumes for play the rest of the year. They get worn more in a few play sessions than on Halloween.
Also, roasted pumpkin seeds are easy, healthy, and delicious.
I wonder if after growing, harvesting, shipping, etc. a Halloween pumpkin is carbon negative.
If I had to guess, probably 80% of the stuff I've received over the years as Christmas gifts ends up getting used very little and then unceremoniously put on a shelf or in the trash. And that may be a generous estimate.