Sure, if we want to subsidize stay at home parents for young children that's a reasonable choice. But, pushing daycare out of reach of most low income family's pushes people into poverty which also has significant long term negative impacts on those same children.
Results are best when there is a single primary care-giver and a small number of other regular care-givers, and day-care tends to not allow for this.
Things get much worse, however, when the staff of the day-care is either too few or too neglectful, as human contact and interaction is so important for early development.
It is possible that we could create a sufficient facsimile of a human to allow for automated care of a child that would fulfill these needs, but there is a creep factor in that, and there remains the question of how one would ethically test the efficacy of such a system.