and their profit margin on your labor and risk and work is far higher than yours.
It's nearly all pure profit for them. They don't contribute to your payroll, they don't contribute to your inventory. They don't contribute to your building rent/mortgage/upkeep.
One could argue that they provide infrastructure, if they ignore the fact that you as a taxpayer pay for the roads, water, gas, electric, sewer, mail service and hired muscle...