Black Friday shoppers wait to enter the flagship Macy’s store in New York City on Nov. 26. Across the country, many stores were closed Thanksgiving, and holiday hours at certain malls and chains will be shortened this holiday season, in part because of a national labor shortage. And many people are bracing for a dearth of products as “supply chain issues” becomes the refrain of 2021. There also are those customers who will stay away from stores, based on new habits adopted during the coronavirus pandemic or ongoing concerns about the virus, and opt to shop online or use curbside pickups.