Aiming is very difficult and that is why I will leave the game

I’ve played halo multiplayer my whole life. There are many things that I do not like about this halo but they are things that I can let go of because in the future they will surely improve. But what if I don’t let go is that targeting and killing enemies is so difficult.
My performance in multiplayer has always been positive, I am not good but I am not bad either, I am very mediocre.
But this game is absolutely horrible the shields take a long time to drop and the bullets seem to hit it.
All the parties feel very frustrating and the level gap is enormous.