I was a technically literate manager, having done lots and lots of programming myself. My job was simple: run interference with the client so that my team stayed funded. The team was very happy to let me do that job, which required a lot of travel and unpleasant politics.
In turn I trusted the team. I asked them for realistic estimates to give the client. If the team thought they weren't going to make it on time, I asked them for a heads-up as far ahead as possible, and I would take the news/new estimate for the client. I did not criticize the team, either to them directly or to the client.
They knew they were asked to do their best but software being what it is, they were not held to preliminary estimates. (The only issue was with downright incompetence or negligence, which was very rare.)
It's interesting that I was considered a good manager by the staff and the client, but not by my own management, who said I wasn't hard enough on the staff. Well, sorry, I got results and I kept us funded.
So, was I a "useless manager"? I hope not. I didn't produce anything tangible, and that bothered me, but I hope I played a useful role.