The adage "good leaders make themselves unnecessary" applies.
If you have people under you, or can coach your people to take parts of your responsibilities off you, I think that's a great outcome. If your ICs are so good that they can actually do that, you should give them a raise and be glad you get to focus on other things in the meanwhile.
Of course, if the manager is unable to then broader their own scope, they indeed become disposable.
