Because we have plants at home, duh. 💁🏻‍♀️ (but that won't stop us)

Propagating a plant by cuttings will allow you to keep the special characteristics of that plant. Plants grown from seed will often be different from the parent plant and from each other. Propagating a new plant via cuttings avoids the difficulties of propagating by seed. (Purdue University)

There are many ways to propagate a plant and each plant will need a different style. Vining plants, like the philodendron, often have little spiky points at the base of their leaves called "nodes". Just below the node is where you would cut the stem to propagate. The nodes will eventually (usually) turn into roots with enough time, patience, and rooting medium. 

As an added bonus, you can visualized your enemies as you chop away. Plants are like therapy, only cheaper....sometimes.