Sometimes the core sector makes a boatload of money, and the people supporting that work in turn get promotions. Companies tend to try to minimize churn in "staff" roles as there are fewer people ready to step in and replace the person who left. Similarly, recruiting for staff positions is often harder than line positions as folks often want to work on the core product mission of a company.
As an analogy, consider the lone sysadmin maintaining the lone linux server hosting a multi-billion dollar companies ERP, Billing Software, and website. The company probably cares enough to ensure this person has a backup, and is paid well enough not to leave. If the everything works the company probably doesn't care enough to do a migration to a SaaS provider, replacing this admin is likely very expensive.