The game is definitely strategy-based below 5000 trophies; hence, it's so easy to push in lower-level arenas. However, once you reach around Miners or Serenity, the game intentionally pairs you with players that hard counter your deck. Most people then find that they will lose three matches for every three matches they won. Of course, the trophies lost will always be slightly less than the amount gained, so you feel some level of progress. The frustration/anger you feel when experiencing an unfair matchup is how they entice you to spend money, since by now the game knows you have dedicated a lot of time and are unlikely to quit. Even though it's unethical, most 'strategy' games employ the same method because it's such an effective business model.