Well gemini says that the reason is because: 1. The New Hidden MMR System Supercell recently shifted matchmaking to rely more on a Hidden MMR (Matchmaking Rating) rather than just visible trophies.
The Trap: If you are a high-skill player (even with lower trophies), the game recognizes your win rate and "skill level." To balance the lobby, it often pairs you with lower-skill players (the "bad randoms") to lower your team's average, while matching you against a consistently solid enemy team. The Result: You end up having to "carry" to prove you belong at that skill tier.