How do credit card “rewards miles” work?

This is about my Capital One Travel card. I get “rewards miles”, have racked up about 10K. I know it’s not a direct correlation to miles I can fly like the good old airline miles, but when I look at flights through the app it says my 10K rewards miles = …a whopping “$100 to be spent on travel”. Kind of a bummer, but I’ve seen posts saying you can use the miles right and find a good enough deal to make them worth more, but is that true? Is that maybe different cards? Is this card a scam* when I could be getting higher monetary rewards with something like Discover?

*I know it’s not actually a scam as in it’s legit but it doesn’t seem worth it if the rewards end up being so low.