Pirates were surprisingly democratic. When booty was distributed, each member would get a share rather than wages.
Some people got more shares than others, that's true. A cabin boy might only be worth half a share, the quartermaster might be worth a share and a half, etc. But most people got a whole share, and the captain was usually only pulling two shares at most. But shares were agreed at the outset, and everyone knew what they were getting into.
This makes a lot of sense when you're engaged in organized crime against the state. The captain gets final say in most matters, but the risk of mutiny or a crew member turning informant was a sure way to end a captain's career. By splitting the wealth more equitably, the crew becomes more loyal.
You may have heard stories about pirates attacking a ship and then recruiting people from the crew they just attacked. A lot of the time in the stories this is framed as "join us or die" but the truth was a bit different. If pirates were known to kill everyone they meet, people would fight to the death to defend their boss' merchandise. But if the pirates boarded you, you were likely given a chance to surrender in exchange for the loot. Then if they were looking for more crew, they'd start recruiting.
So imagine you're working for a real slave driver (I mean, perhaps literally even), and you get a pittance for your wages. You get raided by pirates, and it's your boss' money or your life. Most people would sooner hand over their boss' money. But then they ask if you'd like to work for someone who doesn't treat you like garbage AND you get a cut of the loot you just handed over. That's a compelling argument.