This is so generic as to be useless. A great manager can read this and nod along to most of the ideas. A terrible manager can cargo cult everything here and claim to be doing a great job.
Broadly speaking, there are two reasons managers fail: either A) they don't do a good job representing the work of their team sideways or upwards or B) they don't do a good job representing and cascading the strategic direction from leadership.
While there are many specific modes of failure, they all essentially boil down to one (or both!) of those gaps. The article talks about the Peter Principle where ICs are promoted without management skills, but the flip side of managers who only studied management with no practical expertise is a greater peril. It's obvious when the former is failing, whereas the latter can spin a web of bullshit long enough to continuously fail upwards.
I don't disagree with your observations of common failure modes, but I actually found this article quite concrete and actionable compared to much of the "productivity porn" that gets posted here.
C) They don't do a good job in shielding the team sideways or upwards from external pressures that are not aligned with the strategic direction from leadership
Your two points are important but the best experiences I had _always_ had a manager who effectively filtered out the noise/nervousness from external sources (including from leadership). That means the manager is likely taking all sorts of blunt force trauma along the way but the team is allowed to focus and be clutch.
I think about this sometimes. What about being a somewhat transparent shit umbrella? Like you don't let the team get hit by the shit, but they know that it's raining shit out there. I think it helps put some trade-offs in context.
This is most of my approach. I let the team know what nonsense is coming from up above, what my strategy is to avoid it, and offer options for suggestions on how else we can deflect the bullshit.
Often, we come up with really good solutions which get sent back upstairs for them to digest and shit back out on us in some other, stupid way.
But at least the team feels valued, understands how they fit into the organization, and understands that if an idea dies, it's because of institutional inertia that is out of their hands. It at least helps with the frustration.
This is just managing down. You gotta communicate with your team about what's going on and why.
Being a good umbrella isn't about hiding the rain, it's about keeping it off of them. In fact, hiding the rain is a bad idea, because eventually, people think they don't need the umbrella.
I acknowledge the reductiveness of what I'm saying, but it's absolutely not transactional. To the contrary, understanding and distilling broad contexts from which you have only partial visibility is incredibly difficult work and easy to get wrong. Influencing without direct control requires sustained learning, relationship building and self-reflection.
My point is that all the nuance and subtlety of management is easy to get lost in (especially if you go straight into management without strong baseline work experience). Coaching, Culture Building, and Career Planning are all important components, but you will not do a good job at them if you don't understand A) the work and B) the business context and strategic direction.
Broadly speaking, there are two reasons managers fail: either A) they don't do a good job representing the work of their team sideways or upwards or B) they don't do a good job representing and cascading the strategic direction from leadership.
While there are many specific modes of failure, they all essentially boil down to one (or both!) of those gaps. The article talks about the Peter Principle where ICs are promoted without management skills, but the flip side of managers who only studied management with no practical expertise is a greater peril. It's obvious when the former is failing, whereas the latter can spin a web of bullshit long enough to continuously fail upwards.