Why would you want to keep track of mates rides?
Aside from the obvious, ‘because they are my mates’ I also race against them, and at the bigger team events, with them.
If you see your mate getting a number of PR’s / KOM’s etc… you know they are riding well, and it is something to chat about when you meet up for a pint.
I also follow some of the riders I don’t know personally but are on the local leaderboards, I do this partly from rivalry but also I want to see the routes they typically use and adjust mine. This was particularly helpful when I got my road bike a couple of months ago and had no idea of a decent loop near me.
I find it odd that the haters try to put it down all the time, I wish I’d thought of it.