I feel like a very narrow definition of "leader" is being used, which is basically equivalent to "manager". But to lead means simply to guide and influence. You

I feel like a very narrow definition of "leader" is being used, which is basically equivalent to "manager". But to lead means simply to guide and influence. You can do that by setting a good example, asking the right questions, and participating in a discussion in order to guide it towards a robust resolution. You can be a leader without having any reports.