The TL is the person who the buck stops with on technical discussions. While part of the job is providing mentoring for junior engineers, they aren't directly responsible for performance management, headcount allocation, etc, in the same way that a people manager is, and people don't usually directly report to them in the org chart.
By definition, no large engineering effort is solitary. It makes sense for the more senior eng to be responsible for the decisions that will affect more people, and that requires talking to and understanding them. If people want the senior eng title, they need to be able to do that kind of work.