I have already given my views on change and progress in the area of history and natural science here:
How can we differentiate between change and progress in the area of history and natural sciences?
I don't wish to repeat the same ideas here. So please read it.
Moral (adj.): Relating to the standards of good or bad behaviour, fairness, honesty, etc. that each person believes in, rather than to laws:
Ethics: A system of accepted beliefs that control behaviour, especially such a system based on morals:
The term 'moral', though it is not fully related to man-made laws, is related to some law and it must be the law of nature. I mean, the law that connects all living beings. So, in ethics also there must be a relation to the natural law.
Though ethics is a system of accepted beliefs, these beliefs must be satisfactory to individual as well as society. If each individual can't progress mentally also, I don't give much importance to such an 'ethics'. Ethics must not be just for living in the society. If it were so, we would be compelled to say that ants-like living creatures might be following ethics...I believe there is nothing good or bad in their living as we have.
Even without any external pressure, following of good ethics would lead to peace. But natural calamity may disrupt this life. Mankind is losing peace of mind in the wake of Covid-19. So at any time peace in the society may be disrupted. So we cannot always say that the peace we see around is due to the progress in ethics.
I understand what you want is about the progress in ethics; not good ethics or bad ethics.
Theists and atheists would have different opinions though, since ethics is related to behavior I would like to say like this: If ethics can lead (I didn't mean, 'to take there') each individual to increase their sattvaguna which leads to Truth-Godliness-Beauty, we can say, that ethics has progress; otherwise undoubtedly we can say that it has change only. Progress in individuals will certainly make good progress in the society also. I would like to give more importance to micro-level. If we believe there is progress in the ethics of the society only, that progress might not be something robust. It might be something as I mentioned above.
'Good and virtuous conduct' is 'sanmarga' in Sanskrit. We can split this word into two -- 'sat', and 'mārga'. And 'sat' has its own meaning--the true essence.. Ethics must lead to good and virtuous conduct that is based on the 'sat'.
These are some of my thoughts regarding progress in ethics. You should try to question from different viewpoints before accepting this answer. We might be able to imagine some of the bad practices prevailed in the society in the past. But it would be very difficult to imagine their bad ethics. Most of us never think/imagine that our parents and grandparents were ethically poorer ... in order to assess our progress in ethics. Same would be the case of their parents and grandparents. Most often the fact also is so.
For extra reading (Just for mentioning the cycle):
The following link might help you to imagine life style and the change in ethics. Try to read at least about the first and fourth yugas in the link.
I believe you might have understood at least about the time taken for the changes in the values of human society.
When people feel they can live independently with the help of the many facility they have, ethics would also change. So we can say developments in the society also affect the changes in ethics. But the changes in ethics may not be abrupt. So it would be very difficult to differentiate these changes.