My anecdotal evidence of the contrary:
I was hired to replace a junior developer at my employer about 2 years ago. When my teammate left (team of two), I was basically handed over the entire mobile app. I even built and deployed an entirely new tv app by myself.
Our dev lead, hired months after me, has been promoted to CTO and even our sole graphic designer, hired many months after me, went from "Graphic Designer" to "Lead Graphic Designer."
So the takeaway here is classic:
As an employee you are seen as a cost, and your boss will gladly let you take on the responsibilities of "Lead XYZ" and pay you as "Junior XYZ" if you let them. I unfortunately let them, so I'll cut my losses and chalk it up to things I learned in my early 20s. Could be worse.
Our dev lead, hired months after me, has been promoted to CTO and even our sole graphic designer, hired many months after me, went from "Graphic Designer" to "Lead Graphic Designer."
So the takeaway here is classic: As an employee you are seen as a cost, and your boss will gladly let you take on the responsibilities of "Lead XYZ" and pay you as "Junior XYZ" if you let them. I unfortunately let them, so I'll cut my losses and chalk it up to things I learned in my early 20s. Could be worse.