Sure, you could do a job for 40 years, and be useless at it every single day of your life. Which is why you want to try and do your best at screen candidates, a

Sure, you could do a job for 40 years, and be useless at it every single day of your life. Which is why you want to try and do your best at screen candidates, and promote based on competency. But distinguishing ICs based on some model of seniority isn’t “usually there to justify the wage band in companies who also hire fresh grads as you can't pay someone fresh out of school the same as someone with 10 years of experience”, it’s done because the person with more competency is more valuable to the organisation.