You know that feeling you get when you see a screaming toddler board a plane? Now imagine that's your work, times a dozen, eight hours a day, every day.
I'm not saying its easy I'm just saying it isn't what you described.
Kids, more often than not, do a very good job of reasonably listening to their caregivers. It's when they get home and are in their safe space around their parents that they feel more free to act like little hellions, for lack of a better phrase (and I sure love my little hellions, lol). That's not an absolute, sure, but it's a lot more representative of the reality of daycares than "it's constantly screaming toddlers boarding planes".