This take and the quoted section don’t seem at odds. A great manager is a blocker and enabler for the “people creating the actual value”. The manager adds value, gets the most out of, helps the team, by protecting the builders’ time, maintaining clear prioritization, watching for bumps in the road and mitigating risks as they arise.
If you are hacking on whatever future greatness but are unable to say no to one-off requests (whether due to power within the org or personal communication style) then you’ll never complete your project. Various people will put tasks on your plate, there’s always more to do, someone up the chain will inevitably come up with a new flavor of the week. The manager who tells those people you are fully allocated and working on your top priority is the only reason you’ll complete your groundbreaking work (in most companies).
If you are hacking on whatever future greatness but are unable to say no to one-off requests (whether due to power within the org or personal communication style) then you’ll never complete your project. Various people will put tasks on your plate, there’s always more to do, someone up the chain will inevitably come up with a new flavor of the week. The manager who tells those people you are fully allocated and working on your top priority is the only reason you’ll complete your groundbreaking work (in most companies).