If you apply your same line of thinking to a physical store then why does any company have more staff than the cashier? The point is that a company consists of way more than just what you interact with directly.

You need staff to clean, staff to provide support for other staff, whether that's catering, technical, or anything else. You need staff to ensure that your operations are not violating any local or national laws. You need to break the company up into smaller units in order to be manageable and you need management staff for those units. The list goes on and scales up as the size of the company grows - especially so when it's an internationally operating company.