For sorting algorithms many of the "algorithmic improvements" are caching / locality / access pattern improvements, as latency differences get more extreme and cache sizes grow. (At multiple levels, L1/L2 vs. RAM, RAM vs. disk, node vs. network.) So it's still very much tied to changes in hardware.

Whether you call that an "algorithmic improvement" or not is mostly semantics, it would not have been called such in the 80s but it would be today - what properties we consider part of "the algorithm" has also changed to meet hardware changes.

Even whether it's "parallelization" is somewhat semantics - if you change an algorithm to avoid a pipeline stall, is that designing it for parallelization? I guess not because it's single-threaded, but again someone in the 70s/80s might say yes because two things are happening at once.