I will absolutely not argue that you should do whatever will make you the most money.
But just as absolutely, a PhD isn't the right answer for a lot of people. I thought about it at various points and it wouldn't have been the right choice for me even taking money out of the equation.
There are no tutions and loans for a PhD. It's free. Additionaly, you earn a small salary that can be bumped up to the median wage with internships.
Imagine spending your twenties without financial obligations, working on one problem you love without it having to make a business sense.