Wow that water was clean and the bettas looked pretty healthy some better than others but with so many like that and not alot of help there's a limit what one person can do, but yeah that was the best setup i'd ever seen.
I got my female betta from walmart, her cup was half filled with water and had no gravel, so being females have short fins she was lucky and could actually tunr around and swim, unlike the males with there long fins. They were in a dark shelf and the water was a little brown, the bettas all were dull colored and had stress lines and had malnutrition issues and lots of torn fins. Once home though, my female betta fully grew in her fins and got amazing color and is perfectly healthy.
Around here every store that sells bettas put them in the tiny plastic deli cup or tiny fish bowl you see at carnivals, some with or without gravel or glass shards. With gravel it makes the water even more shallow and cuts the bettas fins as they cant even spread there fins out! Most arent even covered so the bettas can jump out. And besides water quality they are either overfed or starved (for the ones in the back that go for a week or two sometimes without any attention)
If I worked at these places I would definetly know to rotate the fish every other day so they all get a chance at being seen and cleaned and fed. But most places even if you care have policies so they give there animals bad care.
Like the messed up policy that hardly feeding, more like starving the animals is essential so when they are adopted they are hungry and eat right away. Something that if they get used to the pet store feeding them they wont accustom themselves after adoption being fed by someone else, yeah right! If anything feeding animals before adoption is better, because after they are adopted in a new place they are stressed and may not eat right away, so if they are weak already from being starved at the store they may very well starve to death after adoption from being so weak and ill. Usually amphibians and birds mostly have this problem.