I used to be the same way, let me tell you a story about my metamorphosis from “team-player” to guy who doesn’t give af.
I was working at a clothing store for 2 years. I covered at least 2 shifts a week when people called in because the company refused to give me a full time position (probably because they needed me available to cover everyone’s shifts).
One day my older sister and her longtime boyfriend decided that they would get married the following weekend. I told my boss that I knew it was short notice, but I needed this day off. My boss knew me very well by this point and knew that my sister was my hero and practically raised me. My boss said “there’s a sale this weekend and I can’t change the schedule with just a few days notice, see if someone will switch shifts with you.”
I was stunned, but wasn’t yet the person that I am so I asked everyone who was off that day to switch shifts with me, and of course they would, I’d covered multiple shifts for literally every other employee. They were all “too busy”. Some had a party to go to, some had shopping to do, all were ungrateful selfish assholes. And they were all women, maybe it’s a bit sexist but you’d think there would’ve been some compassion right? Nothing.
I told my boss that no one would swap shifts with me and they were just gonna have to be short staffed for a few hours. She said that if I was late or was going to leave early not to come in, ever again.
I was, regrettably, a timid pushover at the time. So I missed my sisters wedding for a shift at a minimum wage job that didn’t give af about me.
I never covered a shift for anyone there again, and quit a couple months later after making it very clear why.
Fast forward a few years to now: my sister is dead. She died in a car crash last year, and never in my life will I regret anything more than missing her wedding.
I understand that it’s wrong to assume the worst of people based on past experiences. That said, I haven’t covered a shift for anyone at any job I’ve had since. If I get the sniffles I’ll call in and not think twice about it.
These companies don’t give a shit about you, they care about money and convenience, same as every coworker that is willing to complain about you calling in.
Do what’s right for you, every time.
Edit: I forgot to mention that the day of this big sale that I couldn’t possibly miss was one of the least busy days of the season. Practically zero customers and I spent my time dusting. Literally while my sister was at the alter my boss said I could head out if I wanted to make the wedding. With pure rage on my face I said “Are you gonna drive me there? Cause my rides long gone since they had to be there for the wedding. If you do wanna drive me there we can help clean up because it’ll be long over by then.”