I think we disagree a little on the point here.
Say before kids you put £1,000 in the pot and your husband put £3,000 in the pot each month. Total in pot = £4,000. Your contribution is 1/4 of the this total.
Now you have a baby, and childcare costs £1,000 per month.
You have two options:
(1) You work and pay £250 in childcare each month. Your husband works and pays £750 in childcare each month.
After childcare costs, you put £750 in the pot every month, and he puts in £2,250. As before, your contribution to the pot is 1/4 of the total. So you are "taking home some money from [your] paycheck" and you are "able to contribute to the 'pot' of money".
Overall of course you "lose" £1,000 from the £4,000 joint pot each month. Net income is now £3,000.
(2) You give up work and have no childcare costs.
As you are no longer earning, your household "loses" £1,000 from the joint pot each month. Your husband's contribution to the pot remains unchanged. As with option (1), net income is now £3,000.
Either way, you lose £1,000 from the joint pot each month. But the first option means you get to keep your job - something you really want to do, and, IMHO, you should get to do.
The scandal of course is that childcare costs are so high that a couple with a joint net income of £4,000 per month pre-kids instantly "loses" a quarter of that post-kids. It is shocking!