1. he has live plants,
I can change my water 100% and rise off the plants, yet still they make the water look a little dirty,
2. If you don't have anything nice to say then don't say anything at all.
It looks clean in the vid to me.
If it were that dirty, you would definitely see derbis resting on the flat areas.
Knocking someone else's bettas or tanks is very rude though point blank.
It would have been different if you asked when was the last water change, but from what I can see, it doesn't look dirty.