I have to say your question was malformed in the sense that it itself was very ambiguous and outright confusing. Despite this, I think (if I’m not mistaken, and please correct me if so) that your question can be rephrased in the following way, in two questions:
**"Is morality subjective? And what are the pros and cons of applying this moral system?"**
You ended with saying:
You have inadvertantly gave a subjective defintion to morality, i.e. that it consists only of making everyone better off. This contradicts your question a little.
“in the context of right/wrong and good/evil”. What other context is there to morality?
Words like ‘right’, ‘wrong’ and ‘good’ and ‘evil’ are 1) highly subjective, and 2) religious in nature. The only purely natural words I can see available here are ‘advantageous’ or ‘disadvantageous’ to ultimate survival, especially, and foremostly of humans. Which I don’t agree with as I’ll explain.
This is how I look at it.
I am a Christian. I can only see one objective morality (moral system, foundation) - an external one. In my case, this is a moral law giver, or definer who 1) has the right over us in order to be ableto bind us to it and 2) have the oversight needed to make one that isn’t subjective.
Because if humans contain morality and define it within itself, then it is bound to be subjective by its definition. Combining morality aand subjectivity, to me, I don’t know, it seems like a non-word. “subjective” and “morality” together don’t make sense. How can anyone say something is ‘right’ or ‘wrong’ if the next person says it’s fine or actually the opposite? That give zilch meaninig to ‘morality’.
Is morality simply defined by the majority? What they believe is right? That would be a cruel world, if wedid live in a world with those so-called morals.
In summary, morals ought to be objective if they are to be actually just, and if they are to actually have any meaning that doesn’t get redefined as the wind blows. It seems, though, that people beleive themselves morals ought to be subjective and therefore define their own as long as no one else is getting hurt.
Surely no one believes morality to be simply ‘live and let live’, do they? Or 'as long I don’t hurt anyone, then that makes it OK. I can list countless cases where no one but the perpetrator gets hurt, and most of the time no, and it would still (and should!) be considered wrong.
I can clarify any point made and am happy to answer any questions.
(P.S. Notorious for typos, please forgive them )