Seeing the difference between effective and ineffective management, and the frequency of the latter, I'm not convinced it's easy either.
Some developers aren't great at gathering requirements, estimating costs, triaging requests, saying no, or any number of other things... if only because they'd rather be coding. And that's not even getting into what they can mess up when it comes to the actual development portion.
A good technical manager can help cover for their shortcomings, and let them focus on their interests - what they're good at. They're not just an ablative meat shield.
Some developers aren't great at gathering requirements, estimating costs, triaging requests, saying no, or any number of other things... if only because they'd rather be coding. And that's not even getting into what they can mess up when it comes to the actual development portion.
A good technical manager can help cover for their shortcomings, and let them focus on their interests - what they're good at. They're not just an ablative meat shield.