On personal anecdotes, I've used the same internet identity across all platforms and it's not hard to locate my real life identity from there...since like 20 years ago when I got on the internet. So all the good reputation and bad reputation followed me through, and surprised me in best and worst way.
There're times when I wished I had concealed myself saying certain things (or just haven't said it), and times when I felt the joy of recognition when people connected dots about me and became closer friend. Now as I'm getting old, it's just a habit, no longer about risks or rewards.
Yet, both younger me and older me will probably be very indecisive about doing this if they've never done it and are told about all the fortune/misfortune this has brought to me, including meeting my wife and thinking about suicides.