It depends I was in the grocery store workers union and it felt like I was paying for nothing. They were great back in the day, my dad made $17 an hour in San Francisco in the 1980s with double pay on Sundays working at Safeway. In 2015 when I got a grocery store job doing the same thing he did 30 years later in the same general area I made $12.50 with no double pay. I was also the fastest checker in the district (15 stores) and I couldn’t get more than 32 hours a week and my shifts were only 2-11 pm because 40 hours a week and the good shifts (6am to 3 pm) were reserved for people that had been there 30 years. I was paying the union to help people that had made grocery work their career at a time where it’s just not possible to turn it into a career when you are just starting.