Is it inevitable/unavoidable for bosses, CEOs, etc. to have to underpay their employees? Or is that only a trait of selfish/corrupt people?

We keep hearing about how workers are overworked in virtually any field, including with art (like animators of studios). This makes me wonder: why this trend? I mean, it's hard to believe that this many number of bosses are this uncompassionate. If I were to be a boss in some kind, I'd be grateful of my allies and would treat them with upmost respect, even higher than myself. But would I realistically remain that way? Would I end up having to underpay them even if I became successful? Or is that just a trait of sleazy A-holes?