This may depend on the definition of “senior”; which seems particularly inconsistent in our industry. Also, since many job ladders tie seniority to technical talent over all else, we are likely in agreement.
Maybe I should have said “experienced”.
There’s a base level of personal development and experience necessary to effectively support others. Much of the role is dealing with interpersonal and organizational issues, which are best learned situationally. There’s also a level of maturity — which sounds totally patronizing — necessary to handle the inevitable ambiguity and uncertainty of the role, which gets amplified when you are a sink for other people’s anxiety (though this is also a function of organization size).
The three levels of leadership model talks about how personal leadership is an essential foundation for private and public leadership. Which I think captures what I mean here.