I was going off what I figured the poster was getting at: they don't understand how Uber has even 80% of their employees.
Uber is discussing laying off 20% of employees. 100 - 20 = 80.
It's completely reasonable to assume the OP was trying to figure out how they have so many employees, even after the layoffs.
eg look at datastores. If you can fit your data in postgres on a single (potentially really expensive!) computer, you probably need two or three of those computers for a primary plus a couple replicas and a DBA.
Once you outgrow that, going distributed costs a team. There is a big elbow in the cost and headcount curve.
Once you want a different specific capability beyond the standard distributed datastores, that costs multiple teams. Yet another big elbow in the cost and headcount curve.
This happens on data stores, applications, translations, currency, etc etc etc. Imagine a Greek person with a Greek bank account driving Uber in France being paid with an American amex card.