What Lead are you?

While talking to my friend on the weekend an interesting discussion spurred up around the roles we have in our organizations. Top of the mind, recall - Team Lead, Tech Lead, Dev Lead, Solution Lead, Design Lead..Jeez, the list goes on..the thing that I'm not able to comprehend is why do we need so many roles? My observation is that the teams are always self organizing and would naturally select a tech authority [perhaps a new role has been coined ;-)] and would not consult a personally who is formally appointed as Tech Lead.