Bangladesh & India had 2+% growth 20 and more years ago, but 1% now, although their age gap may be larger. Israeli growth rate is 1.6% and 5% in Haredi community.
Another possible factor – dropouts from Haredi community among 20yo is 12% (influx 1%) – 5% in Hasidic, 12% among Litvishe and 30% in Sephardi. These are not OTD, mostly people who associate with orthodox in general or traditional. I can’t find numbers but it is possible that more men are leaving than women.
I wonder whether the open market resists a solution: as it is beneficial for a boy to have more choices, so it makes sense for them to wait and have a “stronger hand”.