Digg:

It had potential, but after becoming an ai news aggregator now there's none.

Lemmy:

Low engagement / kinda dead. Also, I have heard that the growth is slowing down(somebody pls provide a citation for this).

Besides that, it's pretty much reddit, for better or for worse.

9gag:

I just made a post there, my first impressions are not good. Got insulted and my post got removed. Now, that might have something to do with me not understanding how the website works, but only time will tell. I will spend more time there to see if it's worth anything.