Literally an apartheid state and we're rooting for characters that are committed to "keeping it safe" (this means further militarizing the border between Piltover and the undercity and killing children on accident and feeling really bad about it). There's plot elements that expose how bad Piltover is for undercity citizens, but that's just the other half of both-sidesing the issue and calling it a cycle of violence. No, the REAL and IMMEDIATE threat is Silco, the guy actually committed to resistance against apartheid Piltover and even the Good and Right characters are opposed to him - to the point that they're more willing to work with Piltover, the state that has been oppressing them their whole lives and which they constantly talk about how its oppressed them their whole lives, to take him down. There's even the gem at the end where Piltover is on the verge of granting the undercity sovereignty and freedom to end the fighting, but then someone decides to fire a fucking rocket straight into the room this decision is being made in. It almost feels 1 for 1 equivalents being made to Israel and Palestine based on hasbara narratives.
I don't know if I'd say it's 1:1 because it's missing the colonizer aspect, but the artificial division between the healthy world and the underworld (I can't recall the names of the places; I saw this show when it first came out and it didn't work for me) was ridiculous. Both sidesing it was also pretty ridiculous and just feeds the modern liberal's 'both sides bad' understanding of the world. Silco's not a great guy but he's absolutely right if he wants to end this apartheid; no hero is perfect, and some villains are so awful they overshadow the negatives on the villain.
Honestly this is like watching game of thrones and thinking any of the noble families, who are pitting their slave-peasants against one another, are the good guys; heck in real life nobles tended to avoid killing one another and instead only allowed their armies to take nobles as hostages while entirely allowing their armies to kill one another.
EDIT: Oh, also in the real world the guys in that meeting room would've voted to 'mow the lawn' with the underworld, or flat out eradicate the place, and they would've made it sound like they're still the good guys.