Damage taken and why it's important

I play Olaf jungle, I run at adcs as they try to kill me, dealing pathetic dmg as I slaughter their squishy asses. By the end if the game I usually have quite a bit of dmg taken from tanking, most in the game usually. Recently I was checking my Olaf stats in ranked, looked at my 'per game averages' and noticed you can see how many doubles to pentas you usually get, how much healing, dmg dealt, physical dmg dealt, magic dmg dealt, and gold earned but nothing on dmg taken in any form. This made me think about why players love playing damage heavy champs, maybe because those are the only stats recorded.

Tanks sacrifice a lot, engaging, taking agro for the team, dying while maybe only getting 1 assist, they also have nothing to back up what they've done other than the dmg taken recorded at the end of the game, but for some reason those stats arent transferred to my 'per game averages', only the little dmg I dealt because I built full tank. Why not include seconds of CC applied to champions? Why not give credit to the tanks that initiate and protect carries? No wonder no one wants to play tanks. . they get the least credit.