I sometimes find myself in a very similar state but attribute that to poor management (lack of vision, badly set goals, messed up team structure, unclear priorities and responsibilities).

I do fine when incentives, authorship, and responsibility are clear, but disengage when those are diffuse.

This suggests that in your case it might be about bad management too, rather than team vs solo work per se.

And let’s face it, good management and good managers is a much much rarer breed than good engineers.