A phone is a pretty bad proxy for what someone is actually doing with their attention
All that is to say, I don't think this forum is indicative of wider behavior AND smart people definitely inflate the value of "work" and "productivity" they do on their phone. We will never know unless we get Apple data, but I suspect a phone might be like 90% entertainment and 5% communication for most people. Maybe 5% is semi-productive work email, reading an article, etc.
I guess I am not sure if it matters where their attention goes. Although, it might be a bit of selective memory in how social people were before phones.