> No longer purchasing women from fathers is a strict improvement over the allegedly pristine culture of the past.

Blah. This is pious view, and a pious dismissal... not a thought out or real feminist perspective... imho.

The past (and present) is complicated... and patriarchal. Marriage, dowries, other symbols, customs and language around marriage... they all relate pretty directly to patriarchy because marriage was (and often still is) patriarchal.

Intertwined within that web were all sorts of dowry customs. Money can go either way, be symbolic or actual. It can explicitly represent a prospective divorce settlement... etc.

Diamond engagement rings happen to have very little to do with either patriarchy or liberty. They're just common consumer culture in a void that once housed real cultural content, whether those were patriarchal or otherwise.