Is this a good reason to quit?

Anonymous
I’ve been considering looking for a new job because I no longer like retail. I’m graduating this year and I find the job I’m at to be catty and cliquey because I work with a lot of women.
The managers are ok but I think they play favorites. I constantly have heard one talking about other employees and then I’ll hear the next week they were hanging out or something. I’m a good worker and I think they pick and choose who they give all their hours to.
There’s this one girl who is a pretty mediocre worker I’m not being unfair by saying that because I genuinely like talking to her and think she’s cool but she’s by no means an outstanding worker. None of us really are but we all do our job correctly.
She’s my age and not in school or anything but I am so I have limited availability. The girl told me the other day how she was being scheduled for like 9 days straight and barely got to live her life outside the job.
I know she probably has open availability because like I said, she’s not in school but she told me our store manager works her every day for 6-8 hour shifts. She told me that when she came in the manager told her to smile and told her she was her star employee.
I feel like this is favoritism because they’ve cancelled some of my shifts last week when I’ve only had 2-3 scheduled because of short hours. I only have one 4 hours shift next week which is ridiculous. Also I’m a cashier and have been for the past few years. There’s usually one other cashier at a time and they’ve never made me lead and will always make the other cashier lead.
I think some of them think I think I’m above the job because I want to go into media even though I’m nice to them but I’m pretty and have rbf so maybe that adds to it lol. The same manager is nice but every time I do something I’m supposed to at the register, she’s like “Good job, Leah”. And it comes across condescending

Is this favoritism?
Is this a good reason to quit?
3 Opinion