I think the main feature for you could be a wider choice of streaming networks/channels. I don't play games on mine, either (rarely, at least. i like having Hitman Go and Lara Croft Go, and maybe you'll discover some minor exceptions), but the ability to add apps from different cable channels like FXNow, AMC, Bravo, etc, is really nice. Some are already on ATV3 and some aren't. And there are streaming services like Shudder, VUDU, Mubi, Fandor.
So it's not really much about playing games or other apps like that. But more just expanding what video content you're able to get access to, and you might not know what you're missing until you discover them. So I do recommend an upgrade if you want a wider access to video apps.
Also, I like the interface quite a bit more, and talking at the Siri remote instead of typing things in is so much preferable.