There are many MTGArena internet communities and all of them are full of users expressing frustration over their matches and toxic players. After a 1.5 year of playing Arena I see what they mean. I am also becoming tired of playing but I care about collection and I am forcing myself every day, just so I can get gold from daily wins. I have stopped using fun and skillfull decks and started to use cheesy, practical decks, that have a chance to win fast without much interaction with opponent. This way I have become like those other players, who I called toxic, who took away that fun for me.
But this cycle of player burn out is a fault of product design. I believe following changes loosen the pressure of rivallry and encourage having fun, reducing propability of toxic behaviors :
1. Change the proportion of rewards : 750/1000 or more gold for daily quest and 500 or less for daily wins

2. Expose the option to report opponent midgame with automatic screenshot for moderators
3. Eliminate "kill X opponents creatures" daily quest