Question

Why is a tumbler not made with a piece of cloth

Answer 1

if it is made with cloth,the cloth absorb the fluids.
it doesn't have capacity to hold fluids.
they absorb.
moreover,the fluid flows and comes out of the cloth.
thank you.

Answer 2

A tumbler needs to hold water.  Because of pores among the fibres of cloth, water leaks out through pores. 

A tumbler also needs to be rigid/strong, it must retain its shape when we invert it.  When we try to pour water from the cloth tumbler, the bottom of the cloth does not go up. So water does not come out of it. You have to hold the bottom of cloth and lift it up.

Also, cloth absorbs water and becomes wet. It becomes unsuitable.