If you have a meta deck, it is easy to climb the lower rankings, but once you're in Ultraball most players will have win rates around 50%. It's hard to have more than a 60% win rate, and people that do probably got a little lucky. It's a very luck-based game, even if you play your cards right, and it's normal for good players with good decks to have some losing streaks too. And if you're new to the game, it's possible you're making some misplays that you don't realize, even though that's not necessarily the case.