> Once you reach a certain level of seniority/experience you are just way more valuable in the force-multiplying role of "leader" than anything you can do with your hands on the keyboard.
This is the key statement. People don't like to hear this, but the reality is that it becomes incredibly difficult to move the needle to a sufficient degree as a high level IC. There are people who can pull this off, but the number of people who believe they can are orders of magnitude different than those who actually can.
For almost all people, all paths to be worth the lofty title involve being able to have an indirect influence on a larger sphere of influence as their hands on keyboard results only go so far. And however one wants to slice it, these paths start to sound like the types of things that people say they don't want to do when they decry "management". Influencing people, politics, mentorship, building trust & alignment, etc.
Leadership roles provide a clear path forward for this, but while there are other ways they tend to still get poopoo'd by the "I just want to code!" crowd.
Mind you, there's nothing wrong with "I just want to code!", I'm currently in such a phase myself. One just needs to be realistic about what that means for their progression.