That’s all well and fine, and I don’t disagree with any of that. But as someone who’s been in the professional industry for 27+ years, Linked In is the only way to reasonably stay connected with people you used to work with/might want to work again in the future, if you’re not personal friends with them.
As much as the platform is terrible, there’s no alternative for the service they provide to my professional career.
I save the email address and phone numbers of the people I worked with to my address book. Why would I need linkedin for that. I read news of my profession from blogs in an rss reader, so I can stay up to date. I follow specific forums, and comment there frequently. Linkedin is just one more social shit you can live without perfectly fine. Of course if you don’t want to live without it, you can’t