We didn’t do any engagement ring. I had been going dutch on all dates or going without for years in advance of meeting my wife. I guess that was a good preparation for not meeting too many gold diggers. Made it natural that my soul mate would be offended by the diamond engagement ring thing for all the reasons discussed including by the OP. She has a modern sense of gender justice.

We bought cheap bands. I like my band because it shows people what I am doing with my life. It also helps women deal with my animal magnetism. I had the ring charged to suppress the attraction field. I had my face rearranged to be asymmetrical too. Anthropologists believe that sturdy and symmetrical features indicate good genetics and attract females in estrus, which I would unnaturally wish to avoid in a modern civilized society.

My wife works with lots of people from many walks of life and education levels and didn’t want to deal with the confusion of her having children and not having a ring indicating she was approved to do so. I put a tattoo on her neck that says “touch at the risk of disembowelment”. This is in case guys don’t honor that the ring means she is my property.