There is a frustrating thing in online collectible card games that tends to make me tired of them fairly fast: the match making algorithm. It is supposed to pick about equal decks to set against each other but that illusion breaks up if you pay any attention.
MtG:Arena is the latest one I've played and due to the generous amount of cards it gives it's easy to try different decks. In fact, the quest system openly encourages this. When you make a new deck the logic behind the algorithm becomes clear. You play a few games and if your deck works you get a few wins, maybe even a streak - until suddenly you hit a wall. The decks you are put against are not only noticeably stronger than yours but also work on the same logic as yours. Suddenly you get frustrated and see all those cards that could improve your deck... You try a different deck and the result is the same: first you get random decks against you and then suddenly a lot of similar decks even if you had never or rarely encountered those before.
Fuck that. It not only makes me angry about the way I lost but takes away a lot of the pleasure from the games I win. How many of those are the result of the algorithm setting me against decks against which I have an unfair advantage?