Have audio cables really improved in last 20 years?

I feel audio components have improved in last 20 years. Better caps, resistors and so on but is there a really a jump in wire production or technology?  I need to buy some more wire. Is it really beneficial to buy new current wire or will older 10 to 20 year old used high end wire be almost as good. I still have my old Acoustic Zen silver ref 2, JPS Superconductor, XLO signature and others and think they sound very good.