I had a realization that the very existence of private domestic shippers in countries indicates a failure of their government to provide universal infrastructure needed by all citizens.
There may be specialized needs like same-day couriers, special handling requirements and other edge cases, but those should be small specialty houses, not international mega-corps.
You stop at things everyone needs. Hair salons and pizzerias are not needed by all citizens and society would adapt immediately if they ceased to exist overnight.
Shipping includes all mail, physical correspondence, and delivery of goods, including to the stores. Society as structured needs that desperately to operate and would promptly collapse without it.