Wine improves with age. Some wines more than others. Time provides complexity and balance to many wines, especially reds, sometimes even whites, rarely sparkling and rosé. Most of the wine is actually made to be consumed immediately, but then there are some wines that reach their perfect balance of taste really only after a few years and there are also wines that should be uncorked only after 10 or 20 years to discover their hidden charm.
We don't always have time, patience and space to keep bottles for a long time. This is why it is worth buying vintage labels, wines already aged in suitable conditions, ready to be uncorked, perhaps decanted and appreciated on a special occasion.