Convenience is expensive.
The provider does not sit on a shelf, they still need to pay bills to be able to be convenient and reliable.
"According to Care.com's 2017 Cost of Care Survey, the average after-school sitter made about $15 per hour in 2016 -- which added up to about $232 per week for 15 hours of work. That said, that number can vary widely from family to family, based on a number of different factors." -
That price does not include school closures.