But in the yeshiva world, the wife supports the family while the husband learns in kollel. So it would make sense for there to be multiple wives so there would be more income.
There was a story in the news last year about someplace in rural India where one of the main duties of wives is to fetch water from a distant source. Polygamy is legal for Muslims in India but it’s illegal for others. Despite this, among Hindus in this location, widows often become additional wives so they can help with the water fetching. You can google “water wives India” to find more on this.