But most steel is already being recycled, at least in the US, according to the US Geological Surveys [1]

  > Recycling rates, which fluctuate annually, were estimated to be 98% for structural steel from construction, 88% for appliances, 71% for rebar and reinforcement steel, and 70% for steel packaging. The recycling rates for appliance, can, and construction steel are expected to increase in the United States and in emerging industrial countries at an even greater rate. Public interest in recycling continues, and recycling is becoming more profitable and convenient as environmental regulations for primary production increase.

[1] https://pubs.usgs.gov/periodicals/mcs2021/mcs2021-iron-steel...

Maybe. A lot of grades of steel cannot be made from scrap metal. At some point, you have to be able to turn iron rust in new steel, even if that rust comes from old steel.