[dredmorbius]

It's interesting that the USGS itself (your 2nd reference) seems to disagree with itself (my own ref). I'd need to dig further into figures to see how that emerges.

(I'm ... somewhat discounting the AISI data as more likely to be skewed industry-positive, that is, with a higher claimed recycling rate.)

[Animats]

It's hard, but the statistics by usage are more clear. Over 90% of automotive and structural steel is recovered. Rebar in concrete, far lower.