Thats not true the Vibrant stands the test of time for gaming. It plays 90% of most games pretty damn well despite the ancient hardware. Last time I saw my friend test out a game dead trigger ran great on it. And its not so much gaming I care about but I dont want to start up a game I think will be fun in 6 months and it run like . My S3 in my Note sucks and I don't want a repeat experience.
It runs games in low resolution and low texture detail so obviously it would run the game fine however we are talking about high resolution and detailed texture gaming. To me as soon as the phone is not able to run the game in full glory then the useful life of the phone (as far as gaming is concerned) is over. Let me tell you how gaming graphics settings works: Most gaming developer has a game setting file where it is written that during the run time game would chose the graphics resolution and texture details based on the hardware of the cell phone. Now vibrant is sitting at the lowest category devices so it has to run low resolution graphics and less detailed textures so obviously it looks to run games smoothly but when you compare the same game running on any high end phone then you realize that how good the actual game looks like. People who are using old devices did not realize that how good graphics and effect the game has until they see a high end device running the same game. Without knowing this they just keep on thinking that it is the game that has bad graphics and their device is still running fine. I have seen many people on forums and play store commenting that Asphalt 6 had better graphics than Asphalt 7
This is not true as the newer game would always comes up with better graphics however they say it based on their experience. What happens is that their device is good enough to run the Asphalt 6 in full glory whereas their device can only run Asphalt 7 is low settings and they think the game has bad graphics. Games select graphic settings automatically without even the knowledge of the user.
Now lets get to your problem that you are facing with S3. The problem with S3 is that every game developer put S3 in high end gaming device list so the poor S3 tries to run every game in it's full glory but at times the hardware falls short and this is were you see lags and think that S3 is not aging well. Soon S3 would be in low end devices then it would start running games in low detail so people would become happy. To me the useful life (as far as gaming is concerned) of an android phone is 6 months. If the phone is not able to run the game in high details then time to sell it. This is my opinion and your can be different. Only iOS devices are aging well.