Looking from the perspective of 15 years of experience, I never took a tech lead role to lead established teams, it always appeared to me that in such teams there probably already is somebody who organically runs the team and I would be perceived as intruder. But I'm also not good when it comes to politics and people dynamics, and knowing my limitations I feel I can only run teams I build myself.. I'm most likely still not senior enough.

If I was you I would ask myself a question if I'm qualified enough (I mean people skills) to take over such established team, where I could potentially be perceived as unwanted addition- in such case I'd probably not take the challenge.