I don't know for certain, but this is where my strengths lie, and this is where I have experience and connections. If the right opportunity presented itself, I would gladly start another company that promised to be as profitable.
However, this will not be the only company I start, and starting a company in the same field (i.e. games) will increase my chances of success. If I start a company in another field, I'd have to stick to that field to keep this kind of advantage.
It sounds that your goal is to make money to donate to efficient causes, like existential risk prevention. If that is so, I suspect that you aren't being strategic about it, because it doesn't seem like you explored enough other startup options aside from games.
What is the expected value of you exploring other options? I suspect that it's greater than you working on games now, but that the returns diminish somewhat quickly. Here are some ideas that I thought of if you're interested: https://medium.com/on-startups/6ecc143afe65.