This is a common myth that isn’t really backed up by the historical or archeological record. Most pirate crews were not proto-anarchists looking to live a life of absolute liberty. They were more comparable to modern street gangs. The captains tended to be a strongman type leader who imposed their will over the crew through fear and coercion. The pirates themselves tended to be outcasts from society who couldn’t turn to authorities to try to escape their situation for a variety of reasons, mostly because they were criminals who knew they’d be imprisoned or killed if they went to authorities.

Probably the only place where anything close to what you describe ever really existed was small communities in Madagascar which became the inspiration for the probably mythical Libertatia. The communities that definitely did exist weren’t some ideological project to try to craft a society absent hierarchical power structures. They were just small, impoverished communities of families where the patriarchs (the pirates) spent most of their time away (at sea doing pirating) so the communities largely ran themselves without a power structure. This isn’t because they had an ideological opposition to them, but because the authority was the pirate leader who spent 3/4 of their time away (and, therefore, couldn’t do the job of being in charge) and when they were home they spent their time partying.

Because pirate ships were known for their attention to discipline, large scale, and long-term stability?