There is a true asymmetry that's avoided by the anodyne "everyone needs to think about these things" talk. If you take a group of 20 people from your country chosen completely at random, some people are likely to find things being similar with themselves and several people in this group, no matter which group was picked, and other people are likely to find little in similar between themselves and the group for most of the groups.
Social skills instruction is often about how to get along with averaged random groups like this. The first sort of person might find it as useful know-how for a thing they already find agreeable. The second sort of person might not find the initial situation agreeable at all, so the instruction gets the implicit added bit of "first of all, you need to not be yourself".
>"first of all, you need to not be yourself"
Yes, that seems part of it, as long as all you know is "yourself without social skills". With social skills, and leaving some of that "yourself" behind, you will discover that don't just change, or reduce yourself, in a social setting, but become more yourself as a whole. The very definition of "yourself" changes, broadens because of this added experience.