I don't think it's a age thing, more like life getting in the way.
I'm 28 and I've noticed games these days don't seem to keep my attention. Don't get me wrong I still love playing games, but I can't remember the last time I beat a game. Just like you I have priorities from spending time with family/friends/GF, walking my pug, riding my motorcycle, tuning my car, photography and resting after work. Gaming has definitely taken the back burner. Actually I recently started using Twitch a lot more these days. I rather watch people play games at the moment especially after a hard days work. Even though I have a High Endish rig I mostly use it for bills,emails,surfing the net and lastly gaming lol. But I do love building them.