I’ve studied history my entire life. My degree is in History. Your ubiquitous historical “gentleman” is largely a myth, and at best is anecdotal, restricted to a miniscule number of examples, an exception rather than the rule. It makes for good literature, but poor reality.
If you’re a student of history, you may have heard of an 18th century philosophy called “utilitarianism”. It seems to encapsulate your ethical views. There’s never been a shortage of people wishing to live unmoored from morality. But for the rest of us, morality is important.