That "black magic" is just different budget pools.

Taxpayers and shareholders hate seeing lots of highly paid people on the payroll, so instead, you have very few full time employees (usually managers) that fit within your limited hiring budget dictated from the top to show you're a lean and responsible organization that doesn't waste money, and then you have a lot of even more expensive external contractors to balance your needs that are part of a different budget that's less scrutinized because those are not YOUR employees, they're just soulless bills in an Excel sheet, like the one for catering, cleaning, maintenance, etc. which are rubber stamped and nobody looks at.

Blame our capitalist society for hating to see people on the payroll, assuming it automatically means inefficiency.