I have played this game for a couple of years and learned quite a bit. But there's one thing I learned that made me become the player I am today. To be a better player, you have to accept that you are going to lose a lot of games. Not only that, you're going to lose to "unfair/unbalanced/unpopular" runes. I'll go into detail.

One key to being better is not dwelling on a lost because of a rune or combo your opponent used. If there was a rune that said if you play this, you automatically win, there's no doubt in my mind that there would be people playing it. Why? People want to win not matter the way. So your task to being a better player is to accept that you're going to lose games due to imperfections in the game. So what's the solution to that? You dust yourself off, you think of how you could have played differently. You watch that player play other people to see how they counter it. If you complain and "blast" them because they used an "unpopular" way of winning, you will set yourself up to lose in the long run. Every time you see someone play that deck, you've made up in your mind, you're going to lose cause you hav’t worked on countering it.

Another key is realizing that there is a counter to any and every type of deck you play. Eventually, you will play against that deck and probably lose horribly. Again, learn from your games. Complaining sets you back. I know a guy and you may see him in-game by the name of profhulk. Now profhulk is in the exo league but has played over 15k games. You may ask why he isn’t in limited. Profhulk plays whatever deck he wants. Has he lost to 'unpopular' decks? Yes. But he'll say, "They only won cause of rune X" and then, he'll play another game. He doesn't dwell on his loses; he keeps on playing, making him, a greater player.

Another key is that when playing any game in general, you have 2 paths to choose. To play for fun (sometimes referred to as the "fair" way), or to play to win (not always the popular way). Of course, these can be combined but generally it comes down to these 2. You play for fun, meaning you're probably going to lose a good bit of games in exchange for creativity. Or you can play to win, meaning you will play whatever you can to win. Playing to win doesn't necessarily mean you deliberately play broken things, but you play with a mindset that "I'm going to win, not matter what". No matter which path you choose, someone will complain, someone will get mad, but go with what you like, no matter what.

In conclusion, unfairness is a part of the game. You have to go with the flow (adapt to it, use it, or just quit when you face it). This is how you get better. It starts with the mind. If you go into a battle thinking you're going to lose, chances are, you might. Obviously though, practice makes perfect. Playing the ai will not make you better. You got to go through the bad to get the good. So I hope this helps and that you'll look at the game in different way. Not everyone can be number 1, but we All, can be better.