And getting paid considerably less. You're almost certainly providing proportionally more for your pay.
A childcare provider can register and only look after 1 child, usually, but wouldn't because they want/need more income.
Presumably nannies (careworker for children from a single family) are registered childcare providers where you are; would a nanny be subsidised able to get paid with a subsidy?
It's akin to education - the general goal is to minimize the number of students per teacher, not maximize it.
You don't want to minimize students per teacher, you want a healthy number of students per teacher. Class sizes are not optimal at 1. Below some minimum class size (which varies by age group) there is no benefit to further reduction, and sufficiently low numbers can be harmful. That's to say nothing of the additional cost of that labor to achieve such faculty ratios.