I would write. Im not sure if that means novels, short stories, movie scripts, or something else entirely. It would be interesting to be a travel or food writer.
That doesn't sound like it would make a lot of money though (as in, a living wage), unless you are highly successful...
Money isn't the be all and end all to some people, you can live cheaply if need be and still have fun.
In fact I know a travel writer who travels the world and writes articles for magazines. If my writing could just pay for my travel that might be worth it.
I don’t think money is the objective with this sort of question: if you could drop a very well-remunerated job to do anything else, chances are you wouldn’t do it for more money.
Thay could be said of nearly every suggestion in this thread, since the original post assumed developers leaving the tech world.