When I first started gambling, I won some significant amount of money which further motivated me to continue gambling. Like any other gambler, later on I found myself losing more money than ever. Which is why I have always thought about whether beginner’s luck was real. To me, it didn’t make sense that the machine or the game knows if the player is a beginner so there’s no such thing as a beginner winning more than an experienced gambler.
But now that I thought about it, I realized that the beginner’s luck had more to do with the player itself than outside factors. As a beginner, you have no expectations. You do not know what’s possible. What can you win, what can you lose. There is no pressure of playing which is why you are just able to win. But a few rounds after that, you are already expecting to win. There is the need to perform better and get more money than the previous round. And that is the explanation for a beginner’s luck. It’s just our mindset.
Well, we all know this is the platform's part of the plan to attract you and make a progress on their platform. From the beginning of your playthrough, you've been nurtured to gamble more because they already planted to a gambler's mind that it's possible to win. Beginner's luck is something a businessman developed and that's how they managed to make more users to their gambling platform.
Try observing and you'll notice that eventually, that luck is gone.

You are correct in your thinking. The reward distribution algorithm has no way of identifying the person and their gambling experience. Every gambler gets lucky sooner or later. The only question is whether the gambler can take the winnings and leave the gambling site or lose everything he won. Will the gambler then consider that something won? I don't think so. And newcomer seeing the winnings immediately withdraw it, because for him is not so accustomed to spending money in gambling.