Let’s take fitness for example. If I want to lift heavier weights, there’s clear advice I can follow. You’ll get pretty far by following any popular strength program, eating right, and putting in the effort. There’s also a clear way of measuring progress: how much weight you can lift. And if you’re not progressing, there are clear variables you can manipulate: workout volume/intensity/frequency, caloric/protein intake, etc. I’m not saying fitness can’t be difficult, just that the path to improve is more clear.
In contrast, there are way too many variables when it comes to social skills. There are a million (maybe more?) ways you can manipulate your facial expressions, the tone of your voice, the vocabulary you use, how much and how often you pause, how much eye contact you make, I could go on. And even if you have the brainpower to consciously manipulate all these variables at once (you don’t), there is no clear playbook with exact prescriptions you could follow.
But let’s say somehow you figure out what to do, and now you just need to practice doing it. It’s very difficult to get data on what you are doing right and what you are doing wrong. If you’re doing practice problems for an exam, you can just flip the page and check if you got the right answers. How do you do that when practicing social skills? People are generally non-confrontational, so they won’t explicitly communicate when you are doing something wrong (unless it’s really wrong). In fact, they’ll probably do their best to avoid even non-verbally communicating that and try to keep up a straight face, just to avoid confrontation.
So social skills have all the qualities that would make a skill difficult to improve. The advice can be very vague and context-dependent, there are way too many variables involved, and there isn’t a clear method to measure how well you are doing.
So, don’t be too hard on yourself if you’re struggling.