Who here as actually been in one of those dollar stores? I wandered into one (same plaza as a South Asian store I go to for chana dal and ghee) driven by curiosity. Even priced at a dollar, many of the items were overpriced - particularly anything supposedly edible. And this was a dollar store *not* in the middle of nowhere.
I'm not saying that there isn't a crash on the horizon, but it seems clear that the ability to order online (particularly groceries from Walmart) is going to take a lot away from the dollar stores located to take advantage of food deserts - and a dip in dollar store profits is easily explained by shifts in buying behavior - particularly as the pandemic has pushed a lot of people into trying online ordering.