The Wisdom behind Polygamy. The number of single sisters will continue to grow so long as they do not want to be in a polygamous marriage. Some of them may even stay forever single unfortunately and Allah's aid is sought.
If sisters and their guardians would be more open minded the rate of zina would significantly go down. But because they put culture and have been brainwashed by the western, that's why zina is widespread and Allah's refuge is sought and to Him we complain.
“There can never be happiness between a husband and wife except by their combined effort to be patient upon one another and to work in close cooperation towards goodness and joint action in nurturing their children. And Allāh's help is sought.”
السعادة لا تكون بين الزوجين إلا بصبرهما على بعضهما البعض, وبتعاونهما على الخير وعلى تربية أبنائهما, والله المستعان.
al-Imām Muqbil b. Hādī al-Wādiʿī, 'Anāqīd al-Karāmah 1/77
مقبل بن هادي الوادعي، عناقيد الكرامة بالإجابة على أسئلة نساء أهل تهامة ١/٧٧