Dude it is true, I main irelia and know the match up is bad for Irelia after level 6. That matchup basically forces Irelia into going sunfire first item because poppy will destroy anyone squishy.
My friend mains pre nerf Yi and even when he was fed, an even scored Poppy beat yi because Poppy W resistance increase + her passive + the fact she gets tankier when shes low on hp to all source of damage makes it hard for high dps champions who are melee to deal with her because if you have to chase her to fight her she can bait you into following her into a potential stun. Long extended duels are her bestfriend because her shield will always come up and not to mention her E and Q which are essential to her kit, but you cant just stand infront of her either cause you cant keep getting hit by her Q cause it does HP damage. Her damage is better than mediocre while being too hard to duel cause she has too internal tankiness.
And she is a direct counter to Tryna since it doesnt matter if Tryn has all his item. Poppy is too tanky for Tryn to kill while Tryn is too squishy to duel with her decent DPS + cc and chasing potential. Jax and Irelia are the best bet against her but I main both of them and let me tell you its a losing matchup late game. Except for maybe Jax at 6 items but even then Poppy can outplay that duel if she can avoid stun with W and R and bait Jax to a wall.
So a Jax and Irelia main in me and a Yi main both diamond are saying that all of them has a disadvantage against A GOOD Poppy. Its undeniable either cause right now she is the best top laner in the game even in competitive not only in soloque. The whole reason she falls off late game is cause as Irelia I can kill the carries faster then she can cause Irelia chasing potential and damage are both better then Poppy. But even then Poppy is too tanky to deal with and its not like her damage is terrible late game. Making her too good early to mid game while still being decent late game with her disruption in teamfights. It doesnt mean she still cant lose.. I havent lost lane with Poppy yet even though I havent even mastered her. The only time I lost with her is when the jungler camps me, BUT EVEN THEN I still win 1v1. Now that is saying something lol.
She is getting nerf because she is DEFINITELY the best right now in terms of what you want out of your top laner. She was not made to be a duelist (well not anymore) but her outplay between IN every matchup are way too high and its so easy to do.
Like here are the rules when youre facing her:
You cant chase her cause she will just bait you into a wall, so you cant chase her for too long.
You cant stand infront of her or in melee range cause you will just eat a Q.
You have to be smart when her passive is up. Cause she will probably use it to win the trade.
You cant be squishy cause her damage potential post level 6 and with sheen is enough to kill you if she stuns you.
You cant be squishy because her E range is so long she will gap close to you, even use a minion to do so.
You cant dash to her or away from her if her W is up cause youll just take free damage and she'll get away or engage the fight.
If you dont have a lot of damage, you cant fight her. Cause shes too tanky and she does constant damage.
Now that is a lot of things you cant do when facing her.. Riot needs to address one or three of these problems. Like the theory you trade tankiness for damage. But you need both to beat Poppy, but I cant think of any to do that beside Yorick or Trundle but even then they cant both lose if they play the lane wrong.