Yes, if you're not FP ALU limited (which is likely the case if not vectorized), or data cache/bandwidth/thermally limited from the increased cost of fp64, then

Yes, if you're not FP ALU limited (which is likely the case if not vectorized), or data cache/bandwidth/thermally limited from the increased cost of fp64, then it doesn't matter - but as I said that's true for every performance aspect that "doesn't matter". That doesn't mean that there are no situations where it does matter today - which is what I feel is implied by calling it "Ancient".