Why does the bacteria exist?

Question

Why does the bacteria exist?

Answer 1

because there are some things that needs to be decomposed

Answer 2

Being part of evolution, their ability to adapt to environmental changes and most importantly recall Darwins theory.

Answer 3

Because there is a massive niche to exploit.

Answer 4

It has adapted itself to the environment ("survival of the fittest").

Answer 5

because God made them and decided to make them exist.

duh

Answer 6

because they r usefull or even necessary in many aspects of life like:-

decomposition of dead organic stuff

making vitamins like vitK

recycling of elements

production of usefull medical needs [vaccines ..]

also used in industries and many many other benefits