Many managers are some of the least respected people in their company, and thus aren't effective leaders.
however that process can break down either because there aren't very convincing arguments either way about A or B, or because someone is being unnecessarily stubborn. at that point its fair to step in and say 'we can't make progress until someone makes a decision, and since i'm in charge, thats me, and its going to be B'
if someone was being stubborn, then as a manger you have to work with them to either work supportively with them to get them to be more constructive, redefine their role so they don't get in other people's way, or if those don't work, tell them to fix it or find a new job.
if a manager is just to keep track of vacation time and have motivational retreats, they aren't providing very much value. as a technical leader if everyone feels free to completely ignore the direction you're trying set without even justifying why, it can be hard to get everyone moving in the same direction.
interested in counter positions
That is, they should be relatively orthogonal (and they certainly have been in my experience; people with formal authority no one trusted, followed, etc, and devs, even on occasion junior devs, who effectively led teams to success)
If you try to lead, you will create activity that needs to be facilitated. The person who understands the goal naturally has information about what help the workers need in achieving it.
For example, suppose your main goal has three major pieces to it. As a leader, you define the goal and the pieces, and you inspire people to work toward that goal. But this naturally raises practical questions like the relative priorities of each piece at any given time. Nailing down actual the priorities is facilitation because it helps people be most effective at working toward the goal. And who can best understand those priorities? The person who has the vision of the goal in the first place.
'Inspiration' should be added as a trigger for workplace swear-boxes.
People aren't in work to be inspired to work more. The vast majority just want to earn a wage with the minimum possible effort.
In my opinion a leader is someone who shows those people how to achieve the goals the company has set in the most personally-efficient manner. Like following a guide through the jungle, he knows the shortest path and how to avoid the dangers. It's not inspirational it's just rational.
You could appoint a manager in the same jungle but he would just assign resources. "Bob, you're the machete man. Mark, carry these bamboo poles.". The team would then proceed to wander around the jungle.
You can appoint a college graduate as a manager but leaders need both domain knowledge and soft-skills. The military knows this, which is why a green junior Lieutenant is paired with an experienced platoon sergeant.
At most organizations I've been in, we'd struggle if the person in charge of a team (whether the CEO or a functional leader of say Marketing) was unable to both navigate and facilitate.
Could you describe the differences in personality?
Management is inward facing, paying attention to the people you are responsible for, and knowing the right thing that's needed at the right time.
"If you want to build a ship, don't drum up people to collect wood and don't assign them tasks and work, but rather teach them to long for the endless immensity of the sea." - Antoine de Saint-Exupery
Leadership is building the boat, management is making sure the boat gets built, on time, on budget, with the proper permits and inspections, training and safety gear, along with bi-weekly status reports to customers.
Some people confuse one with the other, but to me they're distinct and this is a rough sketch of how I see them as different.
There reaches a point where leadership requires you to take the manager gloves off and get your hands dirty. For small teams or small problems, a good leader/manager can be both one and the same.
However as the size of the team or problems grows, it becomes more difficult (think n^2) to tackle both issues at the same time with the same person.
Management issues (firing, hiring, expenses, budgets) and Leadership issues (decisions, progress, advocacy, examples) on a team of 5 may be doable by one person, but may be stretched with one person servicing a team of 15 or 150.
Or if there is a ton more problems in one area vs. others, the challenge of dealing with that problematic area can leave a gap on the "less problematic" areas, which eventually turn them into actual problems. That's my guess as to what people complain about the most.
Likewise a good "manager" is probably motivated by community-building and completion. A good "leader" is probably motivated by the challenge and the path itself in addressing it.
Now, to the airport!
Given the differing dominant archetypal personality traits required for those distinct modalities, it's unlikely they'd be strongly expressed in a singular person, and there's some reason to think they may be necessarily orthogonal. As their motivational biases are likely to be largely unrelated to each other.