The government usually levy taxes usually with an aim to earn
higher revenues.
Taxing the consumption of goods and services that are consumed
or produced heavily helps the government in preventing over
production or over consumption of certain goods and services that
might harm other's.
For example, the government usually taxes the consumption of
harmful goods like tobacco, alcohol, cigarettes etc.
This will not only prevent the abuses that follow their
consumption but also helps government in collecting large
revenues.
That is, when such goods are taxed, some people will refrain
from purchasing those goods but others who are addicted will end up
paying higher prices to obtain them.
This will eventually Increase the revenues that are generated
from the taxation on such goods.