Modern consent-based morality doesn't work because your existence is entirely unrelated to your consent, so it inevitably devolves into nihilistic faggots whining about how unfair it is that they have to exist and work and struggle and suffer. Traditional inheritance-based morality tells you to suck it up and do your duty, because to do otherwise would be a disgrace to your ancestors who fought and struggled and suffered to give you life.
My own preference is for something somewhat more flexible than that, where it's not a strict caste system or anything, but natural obligations towards your parents and the like are still strongly socially enforced. You can have looser or stricter variations of such morality, but if you dispense with it entirely your society will always collapse in on itself.