Maybe people went to other stores
Costco is a very popular place to shop. You can find almost anything you would ever want at Costco. They sell food, clothing, shoes, medical supplies, household items, paper products, automotive equipment, books, blankets, electronics, office supplies, furniture, appliances, and almost any imaginable item. Christmas decorations and gift items are in great supply at this holiday season.
Salt Lake City has a Costco store located at 1818 South 300 West. According to the website, the Salt Lake City Costco is the largest Costco warehouse in their large chain of stores. With several other locations in the Salt Lake Valley, the Salt Lake City store is not the largest in sales volume although their physical warehouse is the largest.
The Costco warehouse stores are generally very busy, especially on weekends. There are often long lines to check out with items which are being purchased. They do millions of dollars of business volume. They are a membership store, and they are very popular with the general public throughout many parts of the world.
Black Friday (the day after Thanksgiving each year) is considered to be a huge shopping day. With so much online shopping now, it does not appear to be as big as it was in the past.
Of course, merchants want to have huge crowds storm their stores on Black Friday and that whole weekend after the Thanksgiving holiday. That particular Friday is the biggest day of the year for many businesses which sell items which could be given as Christmas gifts. Black Friday is traditionally a "day to shop" for many people in the United States. Others who do not like the crowds make it a point to stay out of the stores on that day.
We happened to be at the Salt Lake City Costco on both Black Friday and on the next day. The store had a lot of people in it both days, but it was not extremely crowded. There were not long lines to check out as there usually are on weekends.
Several registers were closed as there were no long lines of customers. Some people were apparently purchasing Christmas gifts, but checking out was a quick and easy matter.
People had been encouraged and enticed through ads to shop on that day at other stores. Perhaps the department stores, electronics stores, and malls were busier than Costco was.
Maybe Black Friday is just not the same as it once was.