I draw a corollary to how graduate medical education works. You go into residency a fresh doctor with zero applicable skills. You may not even be CPR certified, but you're an MD/DO, and you've matched into a residency. You know less about actually helping people than a nurse who's been on the job for a month. You spend the next 3-7 years working 80-100 hours a week learning your chosen specialty. You become an absolute expert at your specific field. If you're in a surgical field you spend thousands of hours practicing and performing the surgeries you'll be responsible for. You may or may not specialize even further with a fellowship for another 1-4 years.

Then, when you graduate and can start making real money (probably), if you work at a hospital that does resident education, you're almost immediately expected to let the residents do as much as they can safely do, so they can learn. You go from working 80 hours a week performing surgery after surgery at a senior resident to working 30 hours a week watching the senior resident perform surgery.

Similarly (and admittedly it isn't a perfect analogy) as a junior and mid-level you're spending all this time learning how to write real software. Most of it's bad and especially at the junior level you're going to spend a couple years being more trouble than you're worth in terms of productivity. But by the time you're a senior, when you theoretically know what you're doing, you're going to have to spend most or a large portion of your time helping out the juniors in your org.

If you don't want to do that, you shouldn't be accepting senior positions. Or at least, go work somewhere where they don't hire juniors.