Arena after you reach top 300 is mostly determined by all kinds of RNGs, such as matchmaking, team generation, Dodge and crit. Not much strategy involved other than sending the right dino to counter opponent. Strategy and dino variety is actually lower than lower arenas.
Outside arena, you don’t have much to do other than grinding. No unknown exciting dino to unlock, for weeks.
Tornament rewards are actually less than the cash cost you need to spend to level up your team.
Anything else one can do other than quit?