Exactly, there is free fuel and aluminium just floating by, and we are unable to use them to upgrade our ships or refuel them.

Until we make full use of robotics and 3D printing, there is no point of heading far. And we have all the tools.

Distant stars will not be settled by a fast small ship travelling from earth. They will be settled by a city sized monolith produced by harvesting and smelting an entire small moon