I doubt UBI will make everyone stop working. As far as I understand, the point of UBI is to ensure that people are not homeless, have enough to put food on the table and it covers your absolute basic needs. Lets say we implement UBI at 1K/Month which is what people like Andrew Yang proposed. That is not enough to just sit at home all day. You still need to make money but hopefully with that 1K, you won't be homeless (or at least thats the idea).