As you level up in seniority, the lines become blurred on how to juggle day-to-day responsibilities and broader impact.
As a relatively junior or mid-level engineer, almost all of your impact comes from your ability to execute: writing code, fixing bugs, and completing tasks. Contrastingly, at more senior levels, almost all of your impact comes from your ability to influence other people in your organization to make bigger changes not only in the product, but the way they work.
Defined expectations at either end of the spectrum make it easier for people to navigate their remit at these levels.