You conradicted your own satement.
You said 'Why would betta hexes be created if they weren't for bettas?' Then said 'Well the pet stores create the ammonia test kits to make a profit.' Well then why would they not be creating the hexes to make a profit?
The creater of this post needs to get over their ego and accept the fact that we are thinking about the good of the betta, not of you. We really don't care if you don't have enough space, or that betta hexes look better. We care that the animal is getting a good life, as it would in the wild.
Bettas are living creatures, as are humans, and it is idiotic to say that dogs don't pee just because you send it in the backyard every day and don't watch him do it. Take out your gravel. You will see that in a week, if you feed your betta, he will poo quite a bit. Gravel likes to cover it up. And you will also see in another day or so that there is a yellow substance that is like oil forming around the poo. And if you take out the poo alone, this oily substance will go into the water. That is proof that poo affects the water.
Bettas like space, though they don't need it. With proper care they can survive in this environment (hex) But in a larger tank (1 gallon +) he will thrive, and will look better. You can see the difference it makes. Their colours turn vibrant, they swim from side to side, and you will see their fins clearly. And now for this one we are thinking of you... With a 1 gallon, you will only need to clean it once a week (100%) and if it is more than 4 gallons, yoou only have to do water changes.
And when you say you feed your betta... Are you really feeding it? Or is it one of those 'I give it a healthy veggie flake once a day' kind of statements?
The person that gives their betta a pellet per week is really not thinking of the well being of the betta. Even prisoners get better than that... And your betta has not even commited a crime. Really if you decide to feed only pellets, they should be given 2 PER DAY minimum. Don't think about how cheap it is for you. You are responsible for that animal, and should always be aware of this.