To be fair there is enough matter in the solar system to build a couple of dyson spheres. There is a massive dust and matter cloud that extends all around the solar system its unbelievably huge, there is enough matter in that cloud to build a dyson sphere and then some. We always think of the solar like a map, if it was to scale and this full stop "." was earth, the solar system would end somewhere near near london over 100 miles aways. Building a sphere 100,000,000 miles in diameter is easily possible if you had access to the tech and the entire resources of the solar system.
J
Humans are since a simple people, they view things with no sense of its relative scale or meaning to ones self. If for just one second all humanity comprehended the sheer vastness of the universe, we'd never war again.
The universe is over 150 billion lightyears in diameter, it is only 12-15billion years old, and is comprised of hundreds of billions of galaxies each with hundreds of billions of star each possibly with hundreds of planets/moons/planetoids.
Why in Gods name would we need to fight one another if we could access the resources of the universe? Forget star trek and Stargate, any truly galactic civilization would have access to near infinite resources/energy. Their only real limitation would be vision, imagination and capacity. Want to build a ring world? If you know how then it is only a matter of time and building it.