The issue is that the Eldians can't just return to Paradis and say "well, we showed them, we got their most important titan, now leave us be!"

With technological progress, Marley will eventually invent the atomic bomb, and then it's over for Paradis. Actually, now that I mention it I feel like that might happen during the very end of the story; I haven't read the manga, so this isn't a spoiler lol.

But how can Paradis even begin to think they could win a war against THE WHOLE WORLD? And making peace isn't really easy either, because non-Eldians wouldn't want to live among people that might transform into deadly giants any given second.

Phew.

Ah, fuck Sasha dying ... although I'll say it'd have been worse if Conny had died. I was expecting the Sasha-foreshadowing to be a diversion and then Conny bite the grass. Honestly, though, I hate how EVERYONE comes off as suicidal. Seriously, the atmosphere amongst the old main characters couldn't be grimmer. Eren, Mikasa, Levi, Jean, Conny, and most conspicuously Armin. It's like they all full well know "this is gonna end soon and we're not gonna live through it".