Twitter is the only one I use still, for how long tho? Not too worried about them tracking me, Im nobody not doin wrong and have nothing to hide.
Mostly I follow Thomas Wictor, Austen Fletcher, James Woods and a few other interesting folk - fun reads on there... informative.
I dont use Twitter to socialize with friends - I'll do that in the real time real world.. and text them directly when needing communications, I find it odd that folks I know well want to chat it up on a social media platform vs personal phone # - never understood that.
Redington posts up some good reads as does Burkheimer Fly Rods and some of the other fishing sites.