A wife isn’t her husband’s “property” per se, but the way you make a kiddushin on a woman is much like that of an “acquisition” of property (kinyan – “isha nikneis”). However, she obviously can’t be sold, traded, or neglected like personal property. On the other hand, they are “our women”, just like we are “their men”. Maybe before Rabbeinu Gershom we weren’t “their men” as much as they were “our women”.
For most of history Jewish societies were the most liberal, where women were treated with much more respect and dignity than they were in other societies. Today, ironically, the West sees us as being outdated and sexist.