Originally Posted by fish monger
You're right, it's no justification; however, he really does look happy and comfortable. I would never purchase a creature just to prove a point. So, lots of decorations are important ?
Not lots, but a few helps with keeping the fish feeling at home and secure.
When scared they can hide and recover, and also allows them to stray from boredom by exploring.
Also it makes your bowl more visual and gives it more places for the fish to rest and sleep.
As for the bowl.. you said it was 2,5 gallons right? It's fine, you know the thing is "the bigger the better" applies but there are plenty of people who had betta fish thrive in 2,5-2 gallon tanks/bowls.
So I don't see why the fish would be unhappy if cared for properly.