So you probably didn't draw many gem recruits?
It's extremely hard to progress without spending at least some $$$. The noobs that past you probably spent money.
I did three rounds of gem recruits, the first round I was able to build a mono blue deck with Poseidon. This lasted for a little while.
Next gem recruits I was able to get a Necro and Hecate and built a mono dark team. This also only lasted for a little while.
My third and final round of draws I was able to get some hp cards, I now have the flexibility to run any dungeon so I should be able to complete the game.
I've been playing for about a month but I don't have the patience to wait for guild shop.
I did draw white healer at the start.
I think the game is fair IMO I have good cards and only spent about 1000 gems to get where I'm at.
That being said, I would never have continued with the game from the beginning had I not got a healer off the bat, it makes no sense to struggle with inferior cards when you could simply just reroll.