He's talking about opportunities. For sure, if you keep doing what you're doing, you will have consistent income. But what if, one day, your boss came to you with a novel, difficult problem that no one in the company, and perhaps in your industry, had already solved? The argument goes, having an arsenal of advanced math at your disposal would make you more likely to solve that difficult, novel problem, and set you up to be handsomely rewarded.
You don't often get "handsomely rewarded" for doing what people consider to be your job, even if you do it much better than anybody else. The opportunities are when you get to jump to a different role, getting promoted or going to a different company or using your insight to start your own company.
