Riot seems to love the tanky assassin meta
https://www.youtube.com/watch?v=E9O1D6bOYS0
Redmercy has some good points. Riot designed all these champs to be non-tanks and right now every one he brought up has morphed into a tanky assassin type champion.
Here's my big problem with this. As of just a year or two ago, riot hated the idea of a tanky assassin. The whole reason Poppy was reworked was because she was a tanky assassin. Fast forward to today and it seems like riot wants all non-tank melee champs to turn into tanky assassins. It's true that ekko and fizz are finally getting nerfs, but that seems like they were just getting out of hand in the role and not that tanky assassins itself was getting squashed.
You know I'm fine with a champ that can be either a tank or an assassin if they build that way. However it seems a bit wrong for champions who can be both at once with one item build allowing them to do that. I think this also highlights the problems riot has with getting items vs scalings right. This is happening because some melee assassins can get away with 1-2 damage items into full tank and are still able to do their jobs.
You want to know why all these ghostblade>black cleaver korean builds are so popular right now? It's because the meta sucks for ADCs when the champs who can delete them are able to do so while building tank.