The Church structure has been patriarchal thus far, but it is now that patriarchy is passing away as the prevailing culture; so it is now that adherence to an obsolete culture of male domination and female subordination is becoming a cause of the vocations crisis.  The signs of the times are very clear.

All the alternative hypothesis you mention are symptoms that patriarchal ways of articulating and teaching morality are becoming ineffective as cultural evolution unfolds.  Humanae Vitae is good doctrine, but the patriarchal tone of the document needs to be refreshed.  Likewise, the patriarchal priesthood of the Old Law may have seem reasonable until recently, but it is no longer sustainable.  It has never been dogmatically defined to be a matter of faith under the New Law, so there is no dogmatic impediment, and the Holy Spirit will continue to guide the Church going forward.

See the Catechism (1577, 1598) , the Theology of the Body on "analogies," and Amoris Laetitia (54, 156).