Ed Huntress wrote:

Because drawing hardens the steel without coarsening the grain, and because
some of the tensile strength comes from the grain alignment resulting from
successive draws through wire-drawing dies, the properties of the thinner
grades can't be duplicated by heat-treating it. The delivered condition,
as-is, is as good as it's going to get.

I sort of understand how heat-treating hardens steel. So my question
is how/why does drawing harden steel? And for that matter how/why does
something work harden?
Ken