It's difficult to measure whether something is a net benefit for humanity, and even if it were possible, that shouldn't be a factor in deciding whether or not i

It's difficult to measure whether something is a net benefit for humanity, and even if it were possible, that shouldn't be a factor in deciding whether or not it should exist. For example, if candy is potentially net negative to society as a whole but brings joy to an individual, should that person be denied the opportunity to make the choice for themselves and enjoy it? I believe that people should be allowed to make their own mistakes and learn from them. A world in which we prevent people from making their own decisions and only allow them to choose from net positive options is immensely bleak.