We've created a society which economically punishes people for having kids. I don't think anyone should be surprised that the fertility rate is declining.

The lifetime pay for a median UK worker @40yr @35k/yr ~= 1.4mil

The "cost" of two children, with above numbers, for "mean woman" is 20% of pay -- so she earns ~1.1m

Presented on a deathbed: would you have preferred to earn 1.4mil over your working life and have neither of your two children, or 1.1m and have both?

The question would seem an absurdity. Bearing in mind that 300k comes with a lifetime of zoom calls and emails, and not much else.

Now if you want to pay women to have children, that's a proposal I'd be open to -- it would reduce the pay gap by significant tax rises, and so on. Nevertheless, I've not met any mothers who wanted to work more nor would take the trade for 1.4 over 1.1 (this, of course, doesnt control for tax credits or welfare -- which both perform this redistribution anyway).