That's the reality in gambling, some may lucky and win, while others have no chances of winning but lose them all. This is also a proof that luck can happen any time, not actually in the beginning. However, just because we often hear successful gambling stories at the start of their gambling career, this become a reason for some gamblers to believe that beginner's luck exists.
There are some persons who actually did had a very terrible gambling beginning, they didn't get to experience the beginners luck syndrome at the beginning of their gambling career and that doesn't mean they will continue loosing, along the line, some later became successful gambling so it's not going to happen following same pattern for everyone, it's only going to happen in a pattern that will probably to relatable to each individual even if in some cases there's this uniform luck for a group, it still doesn't put out the occasional and known disparities.
I even think that this beginner's luck was made possible because some casinos, physical casinos when they opened up at first they intentionally let the RTP for the casino -150% meaning that all people were experiencing a good win there for the first months and so most other people who had never gambled before were curious to try and once they tried they were winning also. After some months though when the RTP was put in place in casino favor after many customers were reached from the casino then things changed and the pattern of beginner's luck fade away. I think nowadays it is difficult to find beginner's luck as most casinos do not leave the RTP against them once they set up their places be it online or physical casino and so we don't seem this pattern a lot anymore. So it is based more on what a casino does when they start up their business rather than if a person is lucky or not lucky in their first gambling session.