Because it is. In single player games there's usually ways to cheese the RNG or boost your odds as you progress. This is an MMO game, meant to take a while to do many of the things in game. No way to boost your odds for that kind of stuff.
There's also RNG on top of RNG.
Say it's 75% chance to get through door one. Then a separate 65% chances to get through door 2. That's stacking the RNG on top of its self so the odds quickly get lower and lower as you go through. Odds stacking on top of one another quickly gives you VERY 'lottery winning' odds no matter how you look at it.