Floor sweeping, restroom cleaning, and grass mowing should definitely be contracted out. What do you do with the lawn care folks in the winter?<quoted text>
So, you have no one in "your company" to sweep the floors , clean the restrooms, handle customer complaints, do any accounting, mow the grass,etc etc etc.
Many companies also contract out large portions of accounting and payroll functions, or centralize them in one office.
As for customer complaints, well-run companies have very few and the complaints should be handled by the person responsible for the work, particularly in service businesses. Nobody wants to talk to a complaint flunky with no authority.