if I hadn’t been born Muslim, would I have ever actually become one? And is everyone even judged fairly?

I’ve really tried to find the answer to this question especially, I’ve tried online and among friends, but it seems like I get told different things. When I try to find guidance in the Qur’an, I feel like it says both sides, so I’m very confused. I am a Muslim and have always believed in Islam, but right now I’m struggling with questions about how other people may be judged. I’ve been thinking: if I hadn’t been born Muslim, would I have ever actually become one? I don’t know. If I were born in Russia, China, Brazil, or anywhere else, and didn’t believe in Islam but instead believed in Christianity wholeheartedly, would I just be sent to hell? The whole premise of being judged seems unfair then. Who can say I should be judged the same as someone who hasn’t had the same opportunities? If someone truly believes in Christ with all their heart but Islam was never explained to them correctly,( or was, either way they believed what they could) would they just be sent to hell? They honestly believed in what they knew, so how is that fair? It all seems to depend on where a person is born, which feels deeply unjust. I’ve tried researching and asking friends. Some say that if someone knows what Islam is and rejects it, they are a kafir and go to hell. But how is that fair if they honestly believed in what they knew? After all, people believe in what they were taught or born into. I would deeply appreciate it if someone could answer this sincerely. These questions make me think a lot, and I have many more that I’m struggling with.