This is part of it, but everyone to some degree has discomfort with being disliked and will do things to avoid it. At least in my experience, social anxiety is much more about the cognitive distortions that convince you others dislike you, when they may in fact be neutral or even have a positive view of you.
Just as one example, when I'm interacting with someone who I haven't reached a certain level of comfortability with, I'm highly aware of and sensitive to their reactions to me in terms of what they're saying, their tone, their micro facial expressions, etc., and I perceive any small negative reaction as a sign that they don't like me. This usually isn't true! But it ironically has the effect of inducing self-sabotaging avoidant behaviors in me, such as over-censoring of what I say and just general awkwardness around them, which makes it much more likely they will end up disliking me.
Just as one example, when I'm interacting with someone who I haven't reached a certain level of comfortability with, I'm highly aware of and sensitive to their reactions to me in terms of what they're saying, their tone, their micro facial expressions, etc., and I perceive any small negative reaction as a sign that they don't like me. This usually isn't true! But it ironically has the effect of inducing self-sabotaging avoidant behaviors in me, such as over-censoring of what I say and just general awkwardness around them, which makes it much more likely they will end up disliking me.