There really isn't evidence that pro-natalist policies work.
There is limited evidence that it has a short-term uplift, but in terms of driving population growth, the package has to be SIGNIFICANT and far-reaching - increasing the length of paid maternity leave, heavily subsidising childcare, introducing flexible working practices - for it to do anything meaningful to shift the needle. You mention France - yes, they have a very long-established framework of support that is comprehensive and would make people shit a brick if it was introduced over here (the taxes! Dear god the taxes!). Their fertility rate is still in decline at the moment though.
I don't know why you reference Poland - yes, they proudly introduced a very generous cash transfer to incentivise people to have more children. It didn't work. Birth rates saw a modest lift, then immediately flatlined and are now in decline - it is not an example of pro-natalist policy working.
You know what it did do though? Evidentially lift children out of poverty. It's a brilliant example, though I'm sure you didn't introduce it with this intention, of how targeting families with additional cash resources benefits existing children, rather than encourages new ones.
I genuinely hope that if, in the future, you or someone close to you ends up in a bad place, there are fewer people like you around. Because your post is, again, based on vibes, not evidence, and is full of contempt and hate for people that need help.
Lifting the child benefit cap, evidentially, won't encourage parents, feckless or otherwise, to have more children.
Increasing benefits to low income families, evidentially, lifts children out of money, with the evidence showing that it is spent on household essentials.