Splinterlands is one of the best blockchain games, if not the best for a long time, I've been there since alpha, but it's like you said very frustrating when you fight with someone with better collection than you, and that's like 80% of the time, my collection is decent, but nothing is fully leveled up, and I fight in leagues where everything is leveled up.

This will never be a balanced experience. That's my largest issue with the game, it's impossible to balance, there are way too many cards already and more are getting released. The gap between high paying players, mid and low, and free to play will be huge with every new release. Just imagine how much you need to pay to own every card fully leveled up.