Aptitude is the ability to perform a type of work. Tenure is the length of time in job. Their correlation degrades rapidly.
From Professional Aptitude vs. Tenure
Ilya includes a nice graphic here of the idea of aptitude versus tenure. In a past career life I worked with a manager who would frequently toss out the phrase “I have over twenty years experience!” when justifying decisions. We’d joke he’d been showing up for twenty years, whether he’d actually learned anything was up for debate.
Most organizations have a “career resting level” for each job: a level everyone is expected to reach eventually that, once reached, carries no further level growth expectations except for sustained execution and honing of their craft. Unfortunately, it's rare to find well-developed tools and language that gives enough credit, praise, and recognition to this happy steady state. Resting levels are not "easy" levels, they are the personal goldilocks zone: challenging but not impossible, rewarding but not at the cost of all else.
The idea of a resting level is a nice thought experiment now that I’m some-many years into my career as a software developer and I am not yet (and do not appear to be on track to reach) Google Fellow level.