"Trading" was implemented just so the title is true
Clearly the developers don't want us to actually trade. They want us to spend more and more money on the game instead of trading with each other, so they go and make trading really inaccessible. You need to trash FIVE 3 diamond rarity cards just to trade ONE 3 diamond rarity card. That is ridiculous. I don't even see why they didn't let 2 star and higher rarity cards be apart of trade, because the prices would probably be in the thousands of tokens and nobody would trade them anyway!
If higher rarity cards had been allowed I mightve even spent a little money on Mythical Island just to try and get a card that my uncle wants to trade to him. I've not spent money on this game before but I was considering it. But now? I'm never giving them a dime and I'd suggest those who have spent money stop doing so.