CW: graphic descriptions of violence and worse to follow.

Couple things off the bat, I'm going to address Caribbean Golden Age pirates here. If someone has sources on Arabian or Indian or South Chinese pirates or others, I'd love some input, piracy has been present since the dawn of ships all over geography and time. My source here is going to be The Republic of Pirates by Colin Woodard.

Were pirates violent? Sure, violence was the nature of the sea, but they need to be put in context with the time. They're incomparable to the cruelty endured by sailors of official Navies and state sponsored privateers.

For one, pirates operated in a much more democratic and egalitarian fashion. They would share the loot amongst themselves, make decisions by vote, and were known as slave liberators. Indeed, many pirates were freed from slave ships that were commandeered by pirates. On top of that, one of the biggest risks to Navies was not the material piracy itself, but that their sailors would defect to pirates. Sailors and privateers were paid very very little, and even that promise was frequently broken. Many men came home to find out that the Navy did not send money to their families, and found their wives and children starving or thrown out on the streets.

Here's a passage from the above source detailing Blackbeard's boarding of a slave ship, La Concorde that would become the infamous Queen Anne's Revenge

In addition, four of Dosset's men begged the pirates to let them join, including the coxswain and both his cabin boys. The boys, fifteen-year-old Louis Arot and slightly older Julien Joseph Moisant, were the worst-paid members of the slaver's crew, receiving a paltry five and eight livres (0.20 and 0.35 pounds) a month respectively. Young Arot...went out of his way to cause them harm, informing the pirates that they had a secret stash of gold dust hidden somewhere on the ship or their persons. Blackbeard's men interrogated Dosset and his officers, threatening to cut their throats if they failed to turn over the gold. The Frenchmen complied, and were rewarded with the pirates' small, forty-ton sloop; the pirates were keeping La Concorde for themselves. The pirates also gave them "two or three tons of beans" to prevent the slaves from starving

So you can see that there's this mix of fairness and violence. Their crew was diverse, and would often free slaves, but not always. They would take treasures at gun and bladepoint, but not necessarily go through chopping off heads. They weren't benevolent by our standards, but I think we'll need to explore just how deep the atrocities go with the alternative, the Navy.

First, the quarters.

They slept in densely packed rows of hammocks in this dark poorly ventilated space, which reeked of bilge water and unwashed flesh. Lice, rats, and cockroaches swarmed the vessel, spreading diseases like typhus, typhoid, and the plague. Gottleib Mittelberger, who crossed the Atlantic in 1750, reported that the cabins were a place of "stench, fumes, horror, vomiting..."

and so on it continues. Quick aside, these conditions were still better than what most slaves endured on the Trans-Atlantic Slave Trade. Thought I'd throw that in there.

On to food:

The food they were fed was literally sickening. The salted beef and pork that were the staples of the seaman's diet came out of barrels dry and hard at best, putrid and maggoty at worst...After a few weeks at sea, the fresh-water supply turned green and reeking and fueled deadly outbreaks of dysentery and bloody flux...Especially greedy merchant shipowners regularly tried to boost their profits by understocking the crew's food supply, leaving them to face starvation"

These things aren't exclusive to the Navy, of course seatravel by its very nature is a hellscape and still is quite arduous. But generally most people in piracy were doing so for a better life than the Navy, they had the budget to treat themselves.

Here's where things get...sickening. I will never forget this passage so long as I live. If you're squeamish, feel free to skip this part.

Then there were the truly sadistic captains. On a journey from Charleston to Bristol, Captain John Jeane took a dislike to his cabin boy, whom he had whipped "several times in a very cruel manner" and increased the pain by pouring pickle brine into the wounds. Jeane strung the child up to the mast for nine days and nights with his arms and legs fully extended. He then dragged him to the gangway and trod up and down over his body, and ordered the rest of the crew to do the same. The other sailors refused, so he kicked the boy repeatedly and "stamped upon his breast so violent that his excrement came involuntarily from him."; Jeane finally scooped up the excrement and "forced it several times down his throat." The youngster took eighteen days to die, despite being whipped every day. Just before expiring he asked for water. Jeane rushed to his cabin and returned with a glass of his own urine and forced the boy to drink it. When sailors prepared the body to be thrown overboard, they found "it was as many colours as the rainbow" with "flesh in many places like jelly" and a "head swollen as big as two men's of the largest size." Jeane was eventually executed for his actions.

While this is the most violent account I could find in terms of cruelty, the complete disregard and monstrous treatment of human life was very common. The British Royal Navy expected captains to enforce strong discipline with unspeakable brutality. How can you not see these conditions and want to mutiny and defect to pirates the moment you see them?

Lest I give the wrong impression, I don't want to imply that pirates were angels going around freeing poor souls out of the goodness of their hearts. We're talking about seafaring men in the 17th and 18th century. It's not pretty. There was rape and plunder of towns, and I do not want to downplay what happened to the many victims. While pirates like Blackbeard and Sam Bellamy were known to avoid force and known to be ironclad with their word, others like Charles Vane were known for violence. When his crews captured ships, they would torture everyone aboard. Due to some unholy animosity between Bahamians (where Vane hailed from) and Bermuda.

Here's an account of Vane taking his revenge on a Bermudan ship after their governor messed with a pirate colleague of his.

Dissatisfied with the take, Vane seized one of [Edward] North's sailors, bound his hands and feet, and lashed him to the topside of William & Mary's bowsprit. The pirates then stuck a loaded musket in the sailor's mouth and burning matches inside the helpless sailor's eyelids; if he didn't confess what money was hidden onboard, they would let the matches burn down to his eyeballs and blind him, after which he would be shot....As before, they began beating Captain John Tibby [on a second Bermuda sloop at the same time] and his crew and picked out one of his sailors for further tortue. They tied up the unlucky man, Nathaniel Catling, put a noose around his neck and hoisted him up the mast, kicking and gagging. There he hung, face turning blue, until he passed out. The pirates cut him down and left him for dead on the deck. Some time later, Catling began to regain consciousness. One of the pirates drew his cutlass and slashed the prostrate seaman across his collarbone. He raised his cutlass to continue hacking the man to death, but one of the other pirates stopped him, saying, as Catling later recalled, that it was "too great a cruelty".

Hope this paints a picture for you. Pirates were a very large diverse group of people. Some were liberators, others just looking for their own freedom to do as they please to others. But all in all, it would be dishonest to depict them any worse or even nearly the same as official state-run ships.