True. But it’s not only about thinking. In my experience it’s also a lot about the need for validation/ general independence. Many people (or even most?) need attention and regular pats on the back. Providing 10 people with this validation and attention can be a full time job.
This is about learning management and reminding them that the problems they might come to you with are the ones you hired them to solve, but you can drop what you're doing to help them if they need.
Not so much. I’ve been a manager for over 10 years and I can tell you people vary greatly in how much validation and attention they need from their manager. If you hire the right 10 people you can have uninterrupted stretches of time to do deep work yourself. If you hire the “wrong” 10 people then you can’t (were wrong is in quotation marks because they may not be the wrong hires under other circumstances).