My opinion is that the vast majority of smart people in rich countries can do the most good for the world by “earning to give” and seeking to earn a high salary and giving some of it to carefully chosen charities. If you have the math skills to become a physicist you might be an exception, especially if you can be of direct use to MIRI. My impression is that outside of academia some physicists earn high incomes, so you might want to consider that path.
My opinion is that the vast majority of smart people in rich countries can do the most good for the world by “earning to give” and seeking to earn a high salary and giving some of it to carefully chosen charities. If you have the math skills to become a physicist you might be an exception, especially if you can be of direct use to MIRI. My impression is that outside of academia some physicists earn high incomes, so you might want to consider that path.