I agree with what you’re saying, philosophically. A group is just a framework we put around individuals. That’s how it works in the real world.
But the idea of being able to have an impact on my own has a special appeal for me personally. It’s not a practical thing, which is why it’s escapism.
You can have impact personally. That’s why many people hesitate to join a group and actually do something - they don’t understand only if they are personally active they can matter. Not doing anything because a person feels like activity is not realistic makes people resigned and idle.
Edit: I do understand your feeling of needing to have an impact. It’s important to understand what kind of activity is worth devoting ones self to. I personally feel motivated to be active when I watch superhero movies, so I guess it can have different effects on different people. As always, things are not black and white.