I guess that depends on the scope. For people who like that flavor of social media, Twitter was where it was at, and X remains the main place. But if the scope is 'of all people' then of course it is not true -- most of us (myself included) never got into Twitter or any of the similar social media sites.
I wonder if it's because they don't see other relevant low-cost/overhead solutions. "Follow me on facebook" certainly isn't going to be a win. "Follow me on Bluesky or Mastadon" is going to be ignored. "You can see my comments on insta" won't be relevant. "My TikTok is where it's at" might get you some young followers.
Other solutions (your own blog, medium, substack, etc), all come with more overhead and setup.