Social media is definitely not socialization. In a Venn diagram, the cross section of social media and socialization is tiny.
- A very, very small part of socialization may very, very occasionally happen on social media.
- Social media allows for multiple phenomena to happen, but the overwhelming majority of it won't be socializing.
The issue here is the redefinition of "socialization" intrinsically made by the "social media" marketing campaigns. The solution is a better understanding of what human socialization actually is.
This is not a critique of social media. I like and use it, even though I'd like more diversity. But stop mixing it up with "socialization" because it is not, even if the marketing of social media relies on trying to mix them up.