I don't just send/sent my children to the CM and nursery because I work. I send them because they get things that they can't get from me. And I'm educated, crafty, and love doing outdoorsy stuff.
At the CM my DD now in particular gets a lot of attention from a multi-generational family. In our house there is just me, DH and DS who is only 2 1/2 years older than her. She gets spoiled rotten by, and loves playing with, the CM's school age grandchildren and her grown up son, and not only is she a substitute granny but once DD got used to the beard, the CM's husband is a substitute granddad. DS got a lot of his one to one attention on the fine motor skills he found difficult from her, too - she was much better at providing a routine to practice them than I was. Maybe I should have tried harder, but I can't move a large family into our home, and I am just not the kind of person to provide some kinds of routine.
At nursery they have access to large scale play facilities, the same children to grow familiar with week to week, and many much more creative things to do than I could possibly provide. They have specialists that come in that don't do private classes, they do large scale art and cooking projects, gardening, big celebrations of national events. None of these are in any way the same if done at home.
I go to a toddler group with DD and she just doesn't socialise. She tootles around on her own or she sticks to me. I can't persuade the other children to play with her, they are with their parents. There are few her age with similar interests, so it's not too surprising. It's basically for me. Pretty much all toddler groups are for the parents.
At nursery she has a little fan who greets her effusively every time she comes in the door. This favourite sees her every week and has got to know her. I'm not going to spend two full days every week in the company of other parents/toddlers for her to get to know another child like this. The carers can persuade ALL the children to share and cooperate, teach them to be careful around other children and interact without another parent shielding their PFB.
I can't make an enormous multi-child height project or grow potatoes in our tiny yard, or keep chickens ditto (and not forgetting that I also work) or redecorate our entire house with lots of children's artwork as the seasons change. I can't have the selection of excellent fine motor toys or gross motor apparatus that the nursery have, 10 different bikes on hand to see which one DS is ready to progress to, nor can I provide an on-hand peer for him to share a two-seat bike with when he feels like it.
Childcare is NOT a last resort for parents who must work. If it is leaving children to be wet or upset it is bad childcare. Good childcare provides children with things they can't get at home. Horse you seem unwilling to believe that non-parent childcare can actually provide anything you can't, well that's very nice for you but we aren't all as perfect as you are.