Ethics (as a philosophical field) is about applying some level of rigor to the question "What ought I (and others) do and why?". "An ethical person" is a meaningless statement without an underlying framework of ethics, which obviously is a hotly debated topic, otherwise it wouldn't be an entire field of study.
What studying ethics offers the individual is the tools to analyze their moral beliefs and ensure they are at least internally consistent. That "and why?" is probably the most valuable takeaway from studying ethics. Rather than saying "that act was wrong", a student of ethics can explain, down to axiomatic beliefs, why that wrong. If a disagreement between two people boils down to axiomatic beliefs, then you're never going change each others minds. But a difference in interpretation can be argued with the potential for persuasion.
It also gives you a lot of practice justifying your own actions. Useful, but perhaps not exactly altruistic.
What studying ethics offers the individual is the tools to analyze their moral beliefs and ensure they are at least internally consistent. That "and why?" is probably the most valuable takeaway from studying ethics. Rather than saying "that act was wrong", a student of ethics can explain, down to axiomatic beliefs, why that wrong. If a disagreement between two people boils down to axiomatic beliefs, then you're never going change each others minds. But a difference in interpretation can be argued with the potential for persuasion.
It also gives you a lot of practice justifying your own actions. Useful, but perhaps not exactly altruistic.