Right that's the theory and you can read about it in his various books.
So instead of paying $260k per year for 10 engineers (2.6M), they might pay 451k for 3 "10x" engineers (1.3M). Costs are 50% lower overall, and if the engineers are even 2x more productive than the average you "break even".
Smaller staff means you need fewer managers.
I'm not saying this is actually how it works in real life (can a developer really be 10x more productive? who know). This is just their operating theory.
Source: https://www.levels.fyi/?compare=Netflix,Google,Facebook,Micr...