Each of the 16 personality types inevitably has a unique edge over the others. It does not matter if you consider two particular types as similar in their naming convention say where one out of the four letters changes. Every type of personality has a unique set of attributes that will help or hinder them depending on the context.
Some of the personality types get loved or loathed more than others by society in general. This can occur due to the population census of types found in a given society or social grouping. Popularly found personality types may enjoy the fact that society has kind of responded to their whims and needs first before the rarer types who tend to befall into the victim or alien stereotypes.
So interestingly Socionics represents to me an esoteric knowledge of the social world. Where esoteric in this context doesn't necessarily mean secret since anyone can discover this open kind of source information and learn more about it. By esoteric I actually mean this kind of awareness usually takes a special level of tuning in and mastery of the subject. Thus bringing us back to the unfair advantage that say Socionics can only make sense to a select few types of people of whom they have a better understanding of self and relationships with others. A kind of shield against peer pressure and subtle manipulation attempts as one has a fair sense of good for me versus bad for me relations.
Thanks for reading. Look out for more Socionics tagged content as it becomes available or if you can't wait, go grab yourself a copy of Your Social World Explained which contains a complete analysis of each type including pointers for personal development.