Back then I had some games when i played against poppy and got literally destroyed but i said i must improve to beat her ..
Today i had a game where I played Yasuo into poppy and actually got a lvl 2 kill on her and the things went good but after i came back from base with a lead over her, she just destroyed me with her kit and damage, she has a long stun and she can easy burst you with her q which has way too much damage.
I tiled bcs i had no counter play against her damage and resistence and inted like a angry monkey but somehow i got some kills, farm killing the weaker enemies and we won the game ..
Anyway she is unkillable in late game, she went against 4 enemies, one of them was tristana who was fed and actually, poppy killed her even with the cc and damage she used to get .. and shes not the only champion like this, mundo, malphite are also a great exemples .
Personally i think that the tanks must have great resistence but not such damage .. you cant outplay them bcs they have alot of cc and then there is the damage and they actually burst you ..
Sorry for my bad english, good luck on your games everyone