Absolutely.

Fundamentally, only reading about ideas that you already agree with is bad for you. You will learn less about your beliefs than if you had read something that challenges your beliefs.

Let's say you're very pro-capitalist, and you want to know everything about capitalism, so you read Adam Smith's Wealth of Nations. Great! You learned some things about the historical basis of your beliefs, and there's value in that. So then you read Capitalism and Freedom by Milton Friedman. Okay! So you're tripling down on the same ideas. You probably already know most of those ideas, though, right? There will be some new stuff, but ultimately it's more of the same stuff you already know.

So you try some more recent authors, and give a shrug to Ayn Rand, and you give Lions and Scavengers a shot. And maybe you pick up a new thing or two. But mostly, it's the same ideas that you're already familiar with.

Do you know what none of these books have? An angle of critique (except Smith, sort of). They're all just listing all of the good things about capitalism, and they're not telling you the bad things. Do you believe that Capitalism is a perfect system to organize a nation's economic policy, with no flaws? No? Then you should be interested in someone who elaborates on some of the negative aspects of capitalism, and what can be done to address those flaws, right? Because if there are flaws, you want to know what they are, so they can be fixed, right?

That's why you should read Das Kapital.