Probably, but there are plenty opportunities to learn to cook, but not many to learn lockpicking. Moreover, the argument “don’t teach skill X because skill Y is more useful on average” leads to silly consequences — it entails that you should never learn any advanced or obscure skills, which is absurd. Cooking is also more useful than programming, and yet you can make good money and have fun writing code. The point here is that learning is not exclusive, you can learn both to cook and to pick locks.

>knowing how to cook

One Google query, two attempts and you know how to prepare a dish. It's not as difficult as most people think.

I think being a locksmith earns more than most cooks (although certainly less than high end chefs). Opening locks without keys is a big part of locksmithing.