I'll tell you what balance ISN'T; facing an opponent NG deck that can mill your own deck, effortlessly, to ensure you can draw no cards R3. If that doesn't show the dev team how broken this game is, nothing will.
I would face a Mill deck any day if given an option between them or (SK nonsense, Double Ball nonsense, etc.). Mill is the easiest deck to face against as they put sh*t tempo on board and even with near perfect draws by opponent, you can easily win against it. AFAIK, I would have won against Mill deck 95% of the time. And every expansion, with the amount of powercreep creeping into the game, Mill decks go out of favor real quick.
You need some context man. Swim plays in masters because he is a high level player who plays the game constantly. Masters is the most try hard place to be. I cant speak for masters level because I dont have the time to grind to it but I can speak for up to Platinum and normal games and the other modes and I can say with confidence that LoR is MUCH more diverse than Gwent has ever been. I have had issues with Ezreal in the past but I have had no issues with Ezreal in awhile. I dont see him as being OP and I didn't even know if Ezreal was in a tier 1 deck or not
So take that for what you will.