This isn't necessarily true. There are many families in developed countries that have more than 2 kids. If you limit families to 2 kids then you could see the fertility rate drop lower (ideally fertility and immigration growth together would be under the replacement rate in developed countries).

"It implies that we must force people to have fewer kids, when evidence shows that women universally want to have fewer kids given the choice. We don’t need to coerce them, we need to help them."

This is generally true, but ignores outliers and the association with other factors. You generally only see the decline in fertility rate in areas that have lower infant mortality, which is also usually associated with a more modern lifestyle and economic conditions. You still have a subset of women in developed countries having a ton of kids for other reasons, like they want a big family, or religious things like the Hassidic community.