you get fired if you dont make it to IC3 or 4 (depending on company) eventually, and getting promoted to those levels does require leadership. sounds like bob just wants to work on bug fixes forever, there is no path to promotion there.
It doesn't mean it's a solo project. It just means you have the technical direction and you can let ppl manager to handle ppl side of things and you do almost 100% tech side of work. If you have 0 tech leadership and can only work on tasks assigned to you, you are not even ic4 worthy, that's absolutely ic3 ie ng level.
Again this is more of a feature in big tech where this kind of projects are available