Question

why does the level of water not change when sugar is dissolved in it

Answer 1

because sugar dissolve in water and fix into empty space between molecules.
and hence volume remain unchanged

Answer 2

the level of water doesn't change when sugar is dissolved in it as it is soluble in water it occupies space between the 2 molecules of water.Hence it's level ie it's volume doesn't increases.
your question contained the answer bro.
hahaha