Deadxerox, first time I see your signature. I love it.
I agree fully, fish, all of them, should be kept in a as big tank as possible.
We try to copy nature, or get as close a s possible. we might never be able to copy a full river, like the amazon, maybe, but a 1 or even 2.5g... some people call this a tank... sorry, but this almost makes me cry.
I personally never had Bettas, as i always thought they are too difficult, and not suitable for a community tank. so maybe I lack some kind of knowledge, but anyway, 2.5g, how much space is there to go for a swim? a fish tank is like a prison, our beloved animals spend the rest of their life in it, so lets make it as comfortable as possible. give them space