Grade inflation/deflation

Have u guys wonder what about grade inflation and deflation. Cause I have took classes which teach material of calculus bc/ physics mechE,mainly what students learn in collage and my grades are like high 80s low 90s for sophomore and senior year and 80s for freshmen and junior year . I am international so obv I don’t have credit for them but too me it is kinda unfair being auto reject( that is what my counsellors and people around me ) say for cmu,Stanford & Columbia . My ecs are like good ( nationals basketball & other cool stuff )