The main purpose of aging a pu-erh tea is to give it time for a slow
oxidationby air.

When a tea is highly oxidised already, there will be no requirement
for further oxidising it.

when airing pu-erh black teas for long periods of time, this will
prompt further oxidation which isnt really necessary else the factory
would have oxidised the tea maximally in the first place.

its the easiest for black pu-erh teas to go bad or mouldy due to the
high levels of oxidation and the large degree to which leaf components
break down.

a lot of black pu-erh teas have very strong "shui3 xing4" (water
character) after a period of aging in air, this results in degradation
in quality as such a character in pu-erh tea is undesired. (shui xing,
water character refers to the taste caused by presence of water, i.e
when a tea cake is kept in a very humid environment, it oxidises very
quickly, and goes mouldy, and this tea cake will have a wet mouldy
taste, we call the tea having a very strong Shui Xing, and the taste
is overly earthy)

Airing black pu-erhs for a span of a month or two in perfectly dry air
will aid in removing all unwanted mouldy odours etc and turn the scent
a little sweetish.

i never liked airing black pu-erhs, neither was i really taught to age
them by experienced tea shop owners who showed me the differences in
aged black tea, one that is not excessively aired, which tasted bold,
woody and profound, whilst the other sample being aired frequently,
tasted less woody, a lot more earthy and a less complex aroma.

its all a just of matter of preference for taste.

note that aging can occur in different ways, aging in a confined place
or aging while airing it. even for green pu-erhs over thirty years,
they should be sealed in plastic and should minimally be exposed to
air, so as to prevent loss of the desired tastes and scents in pu-erh.
the process for keeping it for many years is AGING, whilst airing is
for oxidation whilst aging is another issue.

my apologies for not making the distinction between aging and airing
while aging clear. do not confuse these two terms. its perfectly to
age black pu-erh if desired, this causes some minute unclassified
changes in the tea, but its not really good to age black pu-erh in an
airy environment.