Morality always feels objective from the inside, that’s how it works, but it also always takes a value judgement by a person about how they want the world to be to determine the ethical course of action in a given situation. Utilitarianism is no more objective as a moral system than the categorical imperative, and anyone who tries to tell you otherwise is presupposing the value of lives or QALYs or happiness or not!misery or some other abstract number they pulled from thin air. Regardless, of how much math is attached to it, you can’t reason someone out of believing something they didn’t reason their way into in the first place. There is no objectively right thing to do, if someone doesn’t use your moral system, you’re not going to be able to convince them to start using your moral system by arguing for it using your moral system. Your ethical systems aren’t just a given and you can’t treat them as such. Importantly, it will hurt you if you try because it will skew your ability to predict how other people behave and make you miserable when you inevitably overcorrect and just see most humans as evil instead.