In my experience the "mistakes" mentioned in the article are mostly a motivation problem. The assumption is that a successful engineering manager is one that makes their team thrive whereas in reality the companies only reward individual success. Same goes for developers, best developers only get junior->senior promotions while the ones that join the most meetings and do strategical thinking goes towards engineering management and leadership.
1. Still doing much technical work
If the technical work tackles an important bottleneck or solves an immediate internal problem for the company, this will be seen as incredibly valuable (even more so compared to the eng. manager were still a developer) as opposed to delegating it.
2. Not giving (enough) holistic feedback
In my experience, managers never evaluated based on how helpful they are to their teams. They only need to avoid negative feedback, which is not necessarily aligned with being honest and direct to their reports.
3. Doing all the project management
There's an urgent problem. Eng manager dives in, quickly fetches developers from teams and micro-project-manages them until the resolution and moves on. This is recognised as a success.
4. Not sharing enough information with the team
Sharing is good for the team members, not necessarily relevant or hurtful for the managers' success.
5. Not doing one-on-one coaching
Same as above, managers help their reports out of good will if they do but if they are evaluated on their help with delivery and not the health of their team, they do not have the motivation.