Betta Fish: Aquarium size conundrum

So about 6 months ago my wife and I bought a betta. I hadn't had one since I was a kid and I remember people always kept them in tiny little bowls and 1 gallon betta tanks. Our betta was a baby boy veiltail. We got him a 3.5 gallon cube and planted it pretty good. He seemed very happy. He grew up, got big. Even began making bubble nests. Well we took some flak here on reddit saying his aquarium was too small. So we went and got a 5.5 gallon for him, planted and cycled it. Then we acclimated him and made it his new home. However we kept the 3.5 gallon up and running as it had a few shrimp in it. After about 3 weeks. We came to the conclusion that we didn't think our boy was happy in his new aquarium. He started being lazy, laying around on the bottom a lot​, didn't react to feeding time as he usually does, and hadn't made a single bubble next. So after the 4th week we swapped him back to his 3.5 gallon, where he's now completely back to normal. Very active, always swims to the front when he sees us, and is making his bubble nest again.

So I guess my point is, dont ever let other people dictate how you keep your fish, if you feel your fish are genuinely happy. I feel like I just put my guy through a month of torture all because of some comments by some miserable people who believe they know everything. Not every fish is the same and only YOU know whats best for you and your pet.

/end rant