I feel like it's undignified because it sounds to me like saying "You can have money, but since you are poor and don't know how to handle it, we give it to you

I feel like it's undignified because it sounds to me like saying "You can have money, but since you are poor and don't know how to handle it, we give it to you in small daily portions so you don't waste it all at once.". Like parents do with their young kids. If it's basic income, then you should be free to choose how and when to use it. For your example about forgotten payments, the result would be that you did not pay, so potentially you may lose your insurance, or you receive a fine or something worse. That's a decision you should be able to make yourself. If you don't have control over your own money, that's not very dignified.