Why they own these things? Because they paid for it.
How are Netflix stiffing people out of compensation? Netflix pays the rights holders for the right to stream the content.
On your last part you could not be more wrong. Netflix spent over $6 billion in 2021 on original content. Content they created. They pay for the streaming rights to everything that’s on Netflix up front - in 2021 they paid $11 billion to the rights holders of the content in order to stream it on their platform.
You’re trying to justify theft. You’re the one doing the mental gymnastics.
There’s absolutely something immoral about stealing. If you don’t think there is then it just means your morals are out of whack.
You think people renting out their property is immoral? Yeah nah, your opinion on this is wrong.