I typed this up for use on social media but it still applies.. Bowl, vase, same thing.
Hello! Me and *deleted* are here to inform you that a bowl is not a suitable home for a betta long term. It is much too small for them to thrive and they should have a filter and a heater. The filter is because without it, there is nothing to pick up fish waste and requires much more manual work to remove the waste via water changes and vacuuming. In a bowl, that usually involves removing the betta for this process. removing fish from their home puts a lot of stress on them. In which case a 2 gallon or more aquarium is recommended (as a common consensus among fish keepers) as suitable to maintain a healthy betta for its whole life. A heater is also recommended unless your living space is 80 degrees, because that is the optimal temp for them. Without one, it's like putting your betta in a freezer. It's not enjoyable to them or you, because when a fish is cold, they move less often. These are all recommended to help make the betta happier and improve their overall health. Just like you research a car before you buy it, same applies to fish.