This might be somewhat of a controversial take here but i think both of the aot endings could have worked perfectly and had almost no controversy while still delivering the original message if only one thing was changed
Before you drop a comment attacking me im not here to hate on your opinion of attack on titan,i believe its a great story but that there was only one singular mistake that made it worse in my opinion,i would love to hear your opinion on what i wrote down below
Most of the controversy behind the aot endings (beyond the shipping wars which i dont care about ) were due to one single problem,and that is that both endings(chapter 139.5 and the aftercredit scene for the last episode of aot) in their own way enforced the idea that the rumbling was the right thing to do in some peoples eyes,and that perspective came from this:
In the original manga ending chapter 139.5 confirmed that only about 30 years later the entirety of eldia got bombed(as seen by b2 bombers being used)-pointing to the fact that due to eren failing to complete the rumbling resulted in eldia being wiped out
The anime did a different thing but instead what it did is exactly what eren wanted-hundreds if not a thousand years of peace for the eldian people(and if hypothethically some eldians moved to the areas that got rumbled and diversified then maybe also saved the eldian race)
The biggest problem with both of these is that realistically the entire story could have avoided the whole controversy and still delivered the mssage with only one change-instead of the whole world hating eldia it was mostly just marley,and heres why i think that:
Marley was already the dominant world superpower and controlled 30 percent of the land mass so the situation was just as dire and the justification behind zekes plan still existed,the rest of the world already werent going to help eldia because why help one small island nation against the dominant superpower,both of the endings would have still functioned with almost no text change needed for either, in the manga one no shit you got bombed 30 years later you wiped out hundreds of millions and now you dont have the weapons you used to,and the anime ending would just hammer the cycle of violence even more because sure you eliminated the enemy but humans will always keep fighting you only delayed it some time,the manga ending would work better here for the message but both still work contextually
Realistically the biggest problem of the whole manga were not the endings in my mind but just the singular fact of making it eldia against the world instead of eldia versus a giant superpower,one encourages the idea that if the world hates you you should wipe out the world,while the other says that no matter how much violence you commit to win you will never break the cycle which is the message that was originaly intented.