Having 15 bettas I just have to say...mine are housed in those little teenie one gallon tanks/bowls. They are in my kitchen (plenty of stimulation, not locked away in a back room somewhere).Their tanks/bowls are cleaned weekly, no matter what, and I add aqua safe and aquarium salt to their water each change. I have an armory of fish meds for them as well as for my goldfish and tetras. They are considered living, breathing creatures just as my dog and cats. Mine usually live at least 3+ years and my current oldest I have had 2yr 9mo.
While I don't plan on getting any more bettas, these will be kept, cared for and loved until they die. I even have provided for them in the event I should drop dead as my husband is not a fish keeper.