Why am I so insanely weak?

I (18M), am very weak compared to my peers. For context, I am very tall (6’5”) and have played sports my entire life, mainly lacrosse until high school at which point I switched to wrestling and rowing, both of which I did at the varsity level. I went to all the workouts for my sports, and have gone to the gym on/off for the last few years (though have not been at all consistent). The point I’m trying to make is that although I am far from a great athlete, I’m not some super unhealthy, sedentary guy, and although I am quite skinny (165 lb) the bit of muscle I do have is noticeably toned. Despite this, however, I am weaker than even the unhealthiest of my friends and teammates, and have been for as long as I can recall. I can barely do 5 good form pushups and 1 good form pull up. I bench ~100lbs for reps and cannot bench 135lbs. I curl 15-20lbs for reps. I can’t remeber the last time I didn’t get destroyed in arm wrestling. My ankle mobility is so bad that I can’t even do most leg exercises, and instead rely on the erg for legs + cardio. Even on the erg, however, I lack the muscle to pull any good times and instead had to rely on my technique and height to make the rowing team. Strangely enough, though, my back strength seems to be on par with my peers. I have no health conditions or defects that I know of. Does anybody know why my baseline seem so weak? Anyone with a similar story have some advice?