Why is anti Air so hard?

Why is it so hard to counter one of the easiest strats in the game? I do some generic anti air drills every now and then, i played for Like 80hrs ish, im somewhere around P2 and i repeatedly see people that only spam jump into 2mk into driverush 2lp into throw and then repeat above me in elo.

Im obviously aware that im completely dogshit for losing to those people but they are also pretty clearly bad players. They have 0 fundamentals, combos or footsies yet somehow they get to auto win off of spamjumping because i have to consider different angles, spacing and so on. In concept it seems like this is not a strat that should work at this level but evidently i meet enough people that prove me wrong. I play chun so i have an air invincible move and 2 solid anti air normals, i have all the tools to keep this in check and yet i keep getting stuck in weird situations where i seem to whiff it all or just cant keep up while that ryu is probably kicking his feet and singing along to lady gaga while annihilating me.

How long did it take you guys to Deal with this well, how did you learn it and how do you not get depressed from this?