You're weakening the argument here. Don't be so stupid as to say there are wrong and right people who should have children. It is wrong that middle to high earners often feel they cannot afford children, there's nothing wrong with people in lower income situations wanting and having children.
If we are to continue as a country to provide social support to anyone then we need to make access fairer. We do need to make sure access to funding and benefits are available to those who need them to enable them to participate long term in the economy for the benefit of the nation overall. Whether they need the mechanisms to access a small amount of work or to reduce the impact of children on their long term career.
It isn't a problem that people earning above 100k can need this help. Fiscal drag, high taxation, higher interest rates, house prices, high rent, wage stagnation, a generation of parents with high interest student loans, make the "high earner" salary less glamorous then it sounds.
Child care is also a temporary cost, before the availability of state eduction. 20 years ago, £100k salary might have enabled a private education at a local independent day school easily when fees were 12k a year. Now nursery is over double that, people are having to pay it for 2-3 years per child. You wouldn't begrudge the child of a parent earning £100k a state education from 4 until 18 would you? So why are we being so anti child care access for these people too?
Those on about not prioritising the 4% over the 96%, sure but when your paying for the 96% the 4% is not a significant increase. Its a temporary support for people to help them balance family life with their career and long term economic prospects. Let's stop sabotaging eachother shall we? Let's support social mobility where someone without family wealth can be supported and encouraged to continue to grow their career and earning potential. Let's encourage people to be able to have children in their 20s and 30s if they choose to so things like affording childcare aren't the factors delaying children for women into their late 30s and 40s where pregnancy becomes statistically more dangerous.
In the grand scheme of things, its such a small cost for such a big benefit.