Since Superstore is set in a big-box store, a majority of the scenes showed the characters at work. However, most of these characters took the "all work and no play makes Jack a dull boy" mantra a little too seriously, so they spent half the time pranking their co-workers or lazing around in the break room until it was time to clock out.
Staying true to its accurate depiction of working in a retail store, Superstore created characters with unique traits and varying levels of commitment to their work. While some had a strong work ethic that manifested as an obsessive need to go beyond the call of duty, others preferred to do the bare minimum and keep one eye on the clock until their work hours were over.
Garrett
Garret made no secret of his hatred for his job. He mostly worked as the store announcer and also handled returns, so he interacted with customers on a daily basis. Although he complained about work a lot, he was quite civil towards the customers and he did what was required of him. He even said one time that he does just enough work to not get fired.
Since he lived by that principle, he made it a point not to take on extra work or stay beyond his official working hours as long as he wasn't getting paid for it. He'd also gladly take any excuse not to work, without question, like the time Jonah told him they were staging a walkout and Garrett dropped everything without waiting to hear what it was about.
Marcus
Marcus wasn't very noticeable when he started out at work but he gained some enthusiasm for his job with time. He was especially excited for his promotion to Warehouse Supervisor in season 2, even though it didn't come with a pay raise, and he was actually quite dedicated to it. It seemed like he knew how to do his job very well too.
However, he had the tendency to easily get carried away with non-work-related things. Whether it was playing games in the store or advocating for men's rights with Jonah when he found out the store's new parent company, Zephra, had a lady CEO.
Cheyenne
Despite her young age, Cheyenne had an impressive commitment to work. When Superstore premiered, she was pregnant and she stayed at work until she was literally giving birth so she wouldn't miss a day of work or the money. Although this was mostly attributed to the company not providing paid maternity leave, she chose to come to work anyway even when she had a very good excuse not to.
As the seasons progressed, Cheyenne went from a Sales Associate to Floor Supervisor and she was surprisingly good at it. She employed unconventional, but fun ways to do shift assignments, which also helped improve the employee morale of the rest of her workmates. Her addiction to her phone, however, sometimes overcame her commitment to work.
Glenn
Glenn spent a couple of seasons as manager of the Cloud 9 store that the show focused on. He wasn't a very good one though, but he had his pros. The managerial position always stressed him out, leading to him stalling when it came to making decisions and lots of other mishaps. In spite of all that, he always showed up for work and tried his best not to fall apart on the job.
When he gave up his position as manager and became a floor worker, he was eager to do his job, which was indicative of his good work ethic, regardless of the position he was in.
Jonah
A lot of the time, it felt like Jonah spent his workday chasing after Amy, doing romantic gestures or talking to the other employees, or advocating for all kinds of causes. From playing pranks to just plain playing on the job, Jonah rarely ever took his work very seriously.
On occasion, he had scenes where he'd be shown working in the warehouse or helping out at the counters, but other than that, he hardly ever worked, on-screen anyway. But when it came down to it, sometimes Jonah took on extra work—usually to prove a point—like volunteering for a special assignment, despite not knowing that the job was a fun one to help with puppy donations.
Sandra
In one episode Sandra mentioned that she had to catch four buses just to get to work. Her transport woes were the subject of many running gags she brought up in the break room and also evidence of her dedication to work. She did all the work assigned to her without complaining, even when she was assigned to get rid of hornet nests.
By the time the show ended, she was promoted to Assistant Manager for the new fulfillment center replacing their store. She secured the position, thanks to her new take-charge attitude and her hard work over the years.
Justine
Although she wasn't technically a main character, Justine had several appearances on the show as a ing character. She always made statements to appear sexually adventurous, which Mateo, Dina, and the other characters always shot down or dismissed.
Her commitment to work was harder to determine since she had fewer appearances on the show. However, during the season 3 episode, "District Manager," Amy mentioned that Justine was a hard worker. Unlike some of the other characters, she hardly participated in pranks or games unless it was related to work.
Mateo
From the moment Mateo introduced himself on his first day in the pilot episode, it was clear that he was there to work hard and change the world. Throughout the six seasons of the show, he stayed true to those words, going the extra mile to sort clothing according to style, season, and a bunch of other things.
Mateo was mostly driven by his competitiveness, especially against Jonah who'd started working at Cloud 9 at the same time as him. But beyond that initial competitiveness, he maintained his good work ethic when he was Floor Supervisor and later as Amy's Personal Assistant, which he took very seriously and did well, despite having a tiny, dingy office.
Amy
Amy's career growth on Superstore was an impressive one. After years at the store, she became Floor Supervisor, then Store Manager, and finally the Director of Customer Experience. Amy owed all her workplace success to her hard work over the years and good work ethic.
She showed up for work every time and fixed whatever problems arose. When Glenn was fired at the end of the first season for sneakily giving Cheyenne paid suspension as paid maternity leave, Amy led a walkout to protest the dismissal. In as much as she worked hard, she played hard too, sometimes being at the center of pranks pulled by Jonah and lots of other fun stuff.
Dina
No other character was as dedicated to their job as Dina was. She took work seriously to the point of being a little obsessive about it and pushing others to work harder too. She started out the season as an Assistant Manager and demoted herself for a while in the hopes of starting a relationship with Jonah, then later went back to it with extra zeal.
She worked harder than anyone else, sometimes going a little too far in ensuring the rules were followed. When the show ended, she was the manager of the new fulfillment center replacing Cloud 9, a position she got because corporate had recognized how good she was at her job and her amazing work ethic.