Try to imagine modern life without steel. There would be no cars, and no highways for them to drive on. Nor would there be any trains, or rails for them to travel on. There would be no bridges to connect people and no tall buildings for them to work and live in. We would have to rely far more on fresh and refrigerated food because there would be no steel cans. And we would spend a lot of time hand washing our clothes without our steel washing machines.
Of course, not everything in our world is made of steel. Think for example of glass, concrete and the fabrics that we use to clothe ourselves. Yet each of these also depends on steel; glass and concrete are both made using machines that are made of steel, and nearly all fabrics are woven on steel looms and then made into garments using steel needles.