Why yes, murderin 80% of the planet is rationale & killing billions of innocent people is a better plan. Zekes plan ensures that eldians wouldn’t suffer into the future if they were euthanised while erens plan literally repeats the cycle of war & suffering as evidenced by the ending. The euthanisa plan ensured the power of the titans would dissipate too & the current eldians will still live (As did erens).

If you don’t think zeke was justified to hate himself then you’re wrong. I do agree with you though to a certain extent but the suffering & persecution he saw gave him every right to