I am 36 now and a PhD seems pretty much unthinkable. I don't need that much money yet, so a startup still seems very much feasible.
Investing in a startup at least brings a chance for earning more money, whereas I would consider doing a PhD as mostly for fun.
Also, at least in Germany it becomes harder to get grants when you are older. For the common government grants there is an age limit of 30.
Many professors seemed to prefer younger student, too. I was about 31 when I started looking for professors to work with, and many said they prefer younger students.
Investing in a startup at least brings a chance for earning more money, whereas I would consider doing a PhD as mostly for fun.
Also, at least in Germany it becomes harder to get grants when you are older. For the common government grants there is an age limit of 30.
Many professors seemed to prefer younger student, too. I was about 31 when I started looking for professors to work with, and many said they prefer younger students.