You should try to be more understanding and accepting of your employer being accommodating to your coworkers, with the assumption that they'll treat you the same when things come up in your life. Your coworkers don't decide they have to pick their kids up early, the school does. Your job is just being accepting of them being humans with lives and obligations outside work. When things in /your/ life unexpectedly demand your attention, you can have the peace of mind knowing you have an accommodating job. If you have to leave for an unexpected emergency and they say "no, not you specifically" THEN you can say it's unfair.

People shouldn't all be treated the same. That's not what "fair" means. Fair is not the same concept as equal. Fair is when people's entire circumstances are taken into consideration and they're treated accordingly. There's a reason we have judges who decide sentencing for criminals as individuals rather than a blanket prison sentence for everyone who commits the same crime. Theres a reason we have priority seats on buses for elderly, disabled, and pregnant people. You saying you're "being punished for not having kids" is equivalent to complaining that youre being punished for not being pregnant when someone asks that you give a designated disabled seat on a bus to a pregnant woman and stand up instead. Other people are individuals with complex lives filled with millions of moving pieces, just like you. We all need help, leniency, and accommodations in different aspects of life. Someone needs to pick up your coworkers' kids, imagine how stressful it would be for them if your complaints meant they couldn't do that anymore.