Really not a reasonable take. Social media is great for discovering new things, people, and groups of interest. Sure, you can do that outside of social media too, but in a much slower and more limited way.

Also, lots of housebound disabled people use social media for their main source of socializing.

Yes, loads. It’s very useful for non-anonymous groups + events.

I don’t think Steam users really represent the average person…

This is a stupid distinction to make. There is no speech that doesn’t affect people materially.

“Free speech” is a morally neutral thing. Most leftists don’t go on about “free speech” because it’s not a value we hold. We value tolerance of people of different races, genders, sexualities, and so on. The issue is not speech in general – it’s the content of speech that matters. “Free speech” sidesteps the issue of what is actually being said.