If you like what you are doing I say stick with it. I did and am pleased with the choice.
I've known hundreds of Materials Science grads an know of very few who are disappointed with how things have turned out.
One can make a better than average living at it. A few become CEOs.
However, if your life goal is to become filthy rich selling drugs or something else that people can't do without will increase your probability of success (if being filthy rich is "success").
If you like having a clue about about the way things work Materials Science will give you a high probability of success in reaching that goal. Materials Science as the interface between real science and real life is inherently fascinating.
As you've discovered, there are fewer jobs in absolute numbers available than in other common fields. However, there are more available in a relative sense and they are valued; this is constantly validated by survey and salary data. (It takes only one person to decide that the steel is better with a pinch of Niobium in it, it takes thousands of people to use that steel to build things).
The bottom line is to do something worthwhile that you like; it'll pay off in the long run. After all, what good is a life spent not enjoying what you do with it?
Dave