Under a capitalist system, aka most of the world, people's labor is worth money. That means creators are allowed to sell their stuff. An alternative economic model would have the government subsidize artists to produce free art or literature for the public, but a) fat chance of that happening in America in the near future and b) fat chance of that happening anywhere, ever, with porn. So in the meantime, no one owes you porn unless you paid them for it. Be glad there's anything available for free.

Yeah, of course if you upload stuff anywhere, it might get stolen. You just have to hope it won't. A lot of artists do have freebies, like a public pixiv/AO3 account or Patreon posts that unlock a month after posting to patrons, or commissions where everyone gets to see the finished work, but it's only created in the first place because someone gave the creator money. But just remember, people who only do this for fun can afford to just give you stuff. People who do this as a job have to try to monetize it.

So, don't blame the creators, blame the system.