Retail positions are different than warehouse positions. It's like how UPS drivers make bank, but the guys who load the trucks break their backs for scratch (even with union representation!).

There are warehouse positions in Costco as well. Costco seems to skirt labour laws a little less than other retailers.

I worked at UPS as a package sorter/loader/unloader. The money was great and the part time position offered pretty good health and dental benefits. Only issue was the job was hard on my health. Weird hours and repetitive motion can tear your body to shreds if you let it. But the hours were consistent and there were plenty of opportunities to make extra money during the holidays.

Best teenage job I ever had. They treated us with respect and the pay was exceptional for the job, you could live a middle class lifestyle on it. Sundays they paid time and a half. They also had great holiday events, with a very memorable Christmas party I still cherish. I wish more retailers would treat their employees so well.

EDIT: it does go to the top. The CEO resisted investor pressure to reduce wages and perks. Mad respect to him for treating his employees like people instead of cogs.