While that is possible, I think a good manager recognizes these pitfalls. My philosophy is "everyone has to scrub toilets once in awhile - that includes me". You'd have to ask my direct reports but, I'd like to say I lean more toward taking the "grunt tasks" that I don't think are super helpful for my folks' career growth.
Then again, I've been called a bad manager on Hacker News so...
Obviously being a good manager is first and foremost, but
I’ve always had more respect for managers that I know can (even if they never do) do my job as well as bring a manager. Early in my career at a startup I had a manager that was both and excellent manager and right there in the trenches with you when issues arose or business deadlines were approaching. The amount of respect I still have for that individual is immeasurable and I’d go work for them again in a heartbeat if they asked.
And OTOH, nothing worse than a manager that don't know what he wants nor how to do it, but he "will know when it is right", and keep you redoing stuff.
Then again, I've been called a bad manager on Hacker News so...