I disagree with your premise that specialization is much more efficient. In many cases, it is, but in the sort of services that have historically been in-source

I disagree with your premise that specialization is much more efficient. In many cases, it is, but in the sort of services that have historically been in-sourced to the domestic sphere, it isn't. Once you account for capital investment, labor, overhead, profit margin, taxes paid by the customer, and taxes paid by the business, services such as these are priced high enough to be luxuries. If they were efficient, the price would be so low that they would be considered commodities, and they would be the default choice for most families just from a pragmatic perspective. Keeping a cow for milk is not usually economical, and that is why most people dont do that. Doing your own laundry, cooking, and cleaning are economical. Some things are more marginal- tasks such as doing your own car maintenance and taxes require enough investment of tools and skills that many people should not do them themselves, but many people should, too. The special case where it is in your best interest to outsource everything other than your own career best applies to people that have a high income, are very busy, and can easily adjust their working hours per week. These folks are relatively rare. Cost is king.