What is a primary function employers serve by asking about salary expectations early in the hiring process?

Screening candidates against their established budget for the role

One of the principal objectives employers have when inquiring about salary expectations at the outset of the interview process is to quickly screen candidates against the financial allocation they have already established for the position. If a candidate's expectations significantly exceed the budgeted amount for that role, the employer may decide to discontinue the process early. This action saves time and resources for both the organization and the applicant by avoiding further investment in interviews if the financial requirements are fundamentally misaligned from the start. This initial screening serves as a practical checkpoint against internal financial planning for the vacancy.