Wine is a very reactive environment for oxygen. So oxygen will definitely be the limiting factor, because all the chemical reactions have been starved of oxygen (if you’re interested lookup the Fenton reaction). Of course, it’s not always that simple. If you have an very old wine it’s probably been oxidised, due oxygen ingress from the closure, in which case the vacuum is just sucking out the very small amount of remaining volatile compounds. Also, dissolved CO2 is very important in wine, even still wine, so if you have a light bodied, “fresh” wine vacuuming is going to lower the dCO2 - this will generally make it seem worse. Bringing it back to oxygen - increasing dCO2 can be used to increase shelf life, by decreasing oxidation, on wines where you want to limit use of SO2.