People like to consume their alcohol in all sorts of manners, from straight up in "shots", to a very basic mixture of alcohol with, for example, just orange juice, to very sophisticated mixes of several ingredients of which usually one of the main ones is the addition of sugar sweetness as well as fruit flavors in order to cut down on the general perception of the straight bitterness of alcohol when not so mixed. How adults drink their alcohol is their own choice, of which, alcohol, when it is not mixed with anything, is most definitely an acquired taste, obvious to all that it is alcohol, and fairly easy to know how much one is drinking of any type of alcohol, if one pays attention to the amount of alcohol being poured. So that, if one knows that their basic alcoholic limit is three 1.5 fluid ounces of 80 proof, or 40 percent alcohol drinks, of their favorite brand, and their drinks are mixed at exactly 1.5 fluid ounces, than that person is well aware of exactly how much alcohol that they have consumed, and thereby knows their given situation.
However, drinks that you mix, or at mixed at precise specifications, are not the same, not even close to being the same to drinks that are mixed out of sight, wherever that may be, especially made problematic by those that favor sweet drinks, in which, the sugary content of soda, or its equivalency, do a stellar job in masking to a very large extent, the bitterness of the alcohol being consumed, signifying that if one of your checkpoints when drinking alcohol, is your judgment that the more bitter the drink is, the more alcohol that it has, so that when a drink that is overloaded with sweetness is consumed, your perceptions of how much alcohol that you are actually consuming will now fundamentally be in error.
Not only does the sweetness of sugary substances make drinking alcohol far more palatable, it also makes it difficult to know how much alcohol is being consumed, so that, by the time, you figure that out, when you are, for instance, feeling a bit drunk, or wasted, you have already consumed more alcohol than you intended, which places you into a vulnerable situation. Further to the point, sugary drinks can mask not only alcohol very effectively, but psychoactive drugs, so that, because of this masking, you can easily consume a drug that will incapacitate you, typically given to you, by somebody that does not have your best interests in mind.
So too, some people on their own or through peer pressure, take substances such as cough syrup containing codeine, mix it into a sugary soda concoction, in order to get a "high" from doing so, all made far more appealing by virtue of the fact that the drink tastes sweet, so that the perception often made in your mind, is that this concoction is pleasurable, which encourages one to drink more of it, even though the effects of such, are not good for either your body or your mind.
As much as some people love their sugary drinks mixed with alcohol, it is that sugar that unscrupulous people can use to deceive you, and thereby provide you with drinks that have considerably more alcohol in them than what you think you are drinking, or even worse, other substances that will knock your consciousness out, making you vulnerable to those that are exploiters of such, in which the vehicle that they use to take advantage of you, is the sweetness of sugar, disguising the bitterness of their intent.