The aesthetic benefits of adding greenery to an aquarium are undeniable. It provides a natural and fresh environment for the fish, and brings more life to the tank. Plants can also help with filtration by absorbing some of the waste that would otherwise accumulate in stagnant water.
The benefits of adding greenery to an aquarium include: aesthetics (natural and fresh environment for fish), oxygen production, filtration (absorbing some of the waste).
I personally think that aquarium plants are a great way to bring new life into your home and help provide a calming environment for yourself and others.