Gaming used to take a lot of my time, but I quit about 10 years ago, as I realized I had better things to do - though I was still up late :)
For me, the reason is that I feel like I am going to miss out on something, or that I still have things I could be doing, like writing on Hive.
It is after midnight again - I should try to go now, two hours earlier than normal :D
I still play games when I have time but no more online games as those are really addicting and forces me to play so as not to be left behind by other players.
Also, I think tucking in two hours earlier than your usual sleep hour is a good start.