It doesn’t have to pay off right away. It may not pay off for ten years and it could still be worth it.
It might not even be obvious how it pays off when it eventually does. But it all adds up, and if it’s worth doing, it’s worth doing whether it’s obvious or not.
In his book Born Standing Up, Steve Martin says “You will eventually need everything you ever learned.” One day you may need to draw on everything, all at once. Until then the best thing to do is keep learning, and keep your eyes open.