Because in English, simplicity is never an option. 😂 We also use words literally and figuratively quite often. Grip, grab, grasp "Get a grip" for example when one's emotions are out of control. "Grab that opportunity" for example when a good offer is available. "Grasping at straws" for example when one is using weak information to win an argument. I'm a native speaker of English who has been using the language for 70 years. I chuckle at the rules of grammar sometimes. For example, how is it that the past tense of blink, shrink, think, is constructed as blinked, shrank, thought. 🤷‍♂️ Good luck with your learning goals.

Why have one word when we can have three?😂 Grab and grasp are similar. They include the act of moving your hand towards something as well as taking hold of it. (You can also grab or grasp an opportunity.) Grasp is more formal and less impulsive. Grip is the act of holding on tightly to something once it's already in your hand. So you might continue to grip it after you've grabbed or grasped it. Does that help?

FYI, 'cracking up' usually means LAUGHING, although it can mean GOING CRAZY . . . which illustrates/demonstrates/shows your point, actually. English has 10 ways to say everything. I suppose that's its beauty and also the thing that makes it frustrating to learn