1.Very expensive game lol, Buying Battle Pass(costly) is useless if u wont buy the Premium too (another costly), and you need to play all day to lvl it up or u wont reached the maximum lvl of BP every battle only gives extremely little BP exp ( AND u need to WIN it or gained nothing) which is not good for casual players.
2. Lack of content (its been a while) the update has 1 year interval.
3.Unfair matchmaking system
4.Lack of players (rate of new players joining is slower than the number of players quitting) because of the 1-3 issues above.