Maybe I'm wrong here, but I think if you want to solve Epic Problems like malaria and slavery, you are going to have to be ready to put things like buying a house and living where you like in the back seat.
That doesn't seem obvious. There are people working on banking, advertising, business software development, etc. in pretty much every major city. Why shouldn't the same be true of Epic Problems?
You can direct your work efforts towards goals that are important/meaningful to you without necessarily sacrificing everything else in your life. Conversely you can give up a good deal of your life to work on unimportant problems, and many people do.
I'm not saying you can't have any of those things and pursue your dreams, but life is not known for putting your dreams comfortably within reach. Banking is pretty universal (in every city); malaria research isn't.
Odds are at some point you will be forced to make choices; how many people are so lucky that their dream job is walking distance from their dream house in their dream city?
Yes, like someone else said, that's not necessarily true or obvious. There's a DMV in every major city in the country, there are veteran services, immigration offices, department of defense, department of human resources, housing and urban development, and all the other alphabet agencies in almost every major city. There are hospitals, universities, and research labs in every major city. There are police departments, sheriff's departments, SWAT teams, FBI teams, and ATF teams in every major city. And in this day and age, remote work is a thing -- technology in general is a thing.
I don't see any reason I need to give up anything (other than maybe a huge salary) to work on these problems. The true roadblock for me, I believe, is just a lack of knowledge and education on those particular issues.
