A lot of the benefits of gaming that people don't really put emphasis on is that it creates a social outlet for people who don't have any other means of relatable communication with people.
I've seen this especially with the Facebook Page Community. I've noticed that a lot of people are trying to sit on the other end of that "Big people used to always step on me in high school", by having a really popular facebook page and stepping down on people who weren't part of their exclusive group of page friends. They had page wars, page relationships, and even a fucking page homecoming. It was a huge thing to be a big page. Most people that were part of big pages were people who really didn't have much friends IRL. They threw on their fedora and got mad when people were offended by their "le ofensiv humor." They couldn't relate to anybody because they felt their intelligence was much too high for everyone else, and nobody had the same kind of humor or interests as them (It's hard to find someone with an interest in Girl Cartoons and Extremist Republican Propaganda in most high schools). However, when they have this little page community, they find people to really like relate with, and they can live the life they never got to live, being the big shots somewhere, for the first time having influence. It happens a lot with gaming too, where people will have such strong bonds with people that go to a League of Legends Skype Call with them, or end up somewhere on the internet with them. Hell, even I've gone through that. Some of my best friends, I've met through osu! and other games.
Another benefit of gaming is that it stengthens the bonds between people. My brother was not very social at all. He was very smart, but he'd prefer to hang out at home rather than go out with friends on a Saturday night. However, he is able to keep in contact with many of his friends and get involved in many things by his Skype group that he has with his friends when they play DOTA2. That Skype call allows him to talk to all of his friends and have people to be close to in one sitting. It made his college life much easier, as he goes to the same college as some of them, so he wasn't very lost when entering the school (Although he goes to a state school so it's still really big lol). If he didn't have that skype call, or DOTA2, he'd literally be alone, except for his family.
Gaming is also a stress reliever. You know that guy who called you a bitch faggot on TF2 because you didn't heal him fast enough? He's having a medium where he can vent his anger towards other things. He can yell and scream in a medium that is still kind of bothersome, but also gives him enjoyment. Of course, this point isn't as strong, since many times, gaming can actually INCREASE stress. I've had my worst days happen because of rude commentary I was told while playing a game. I've cried myself to sleep based on what people said to me while gaming. I've gotten pissed off because of gaming. But there's plenty of therapudic mediums that can do that. For instance, I'm starting my B.M.E. as a Classical Tuba player, and it's a great medium for me to relieve stress and have fun, but I still shit myself when I didn't practice my B Major Technical Studies, and I still get stressed when I'm not able to do what my instructor asks of me. But I still get enjoyment from my successes and I would be so sad if I ever stopped playing.
haha I just did your entire essay for you at 1:32 AM woo
Also I suggest doing some googling on the subject. I'm not entirely sure of the concept of a free choice senior essay and what the expectations are, (My official "Senior Project" was an group project analysis of a poet who's name I forget. It was like Christina something. So eh) but if it's any sort of decent essay, you're gonna need to cite some sources and stuff. I am not a valid source. If your essay is simply based on the ideas presented here with no real backing, then you're gonna end up not doing very well on your essay, if the essay requires citation. If it's pretty much just a free-write on a subject that you feel like, then that's unbelievably basic for a senior project.