When I Played My Younger Brother's Favorite Game To Exhaust Him

So here’s the thing. I’m twenty-two now and I have a younger brother who is twelve. Lately, he has been super annoying me because we’re both trying to do school online at home but he can’t stay off his games during class hours. It’s really frustrating because it’s so noisy that I struggle to concentrate on my lectures too. Anyway, the other day I had enough of him being disruptive. I tried talking to him about it beforehand, reminding him we have a set schedule and asking if he could try doing work when he's supposed to be in class. But you know how kids are... They just don’t listen or they say they will but then do their own thing. I came up with a plan that I thought would get him tired enough to want to play games less, at least for a while. So I sat down next to him during his math class and started playing Minecraft right alongside him. Now my brother is obsessed with this game - he plays it all the time and it’s practically his whole world. I knew he’d get annoyed if I just joined but not too annoyed because he loves when I play games with him in general, especially his favorites. So that’s what I did. We played for about an hour straight during a math lecture and afterward I pretended to be really tired from all the building and adventuring we were doing together. My thinking was that this would make him feel bad since he loves me spending time with him and he'd start seeing playing Minecraft as something that takes away from real life stuff. It worked in a way because after that day, for about three days, he actually did try to be more productive during his classes without being on the game all the time. But then it went back to normal - every class became a chance to play and I was right there with him too, making sure we played for hours after school as well. And now, not only is my brother playing non-stop like before, but he expects me to be involved in his gaming life all the time when we could be doing something else. Am I really just enabling bad behavior here? Is it so wrong that I used this tactic because I didn’t know how else to get him to focus more on his schoolwork and less on video games? Have any of you ever tried something like this with a sibling or kid who won't follow the rules?