Leetcode is a first-order screen to find people of base-level minimum intelligence and problem solving ability. It's not a quiz of actual problems you'll solve on the job, it's a way to screen out the wannabes who couldn't program their way out of a wet paper bag.

Grinding leetcode also shows you've got grit, and are willing to prepare for a task and do what it takes to succeed.

Grind leetcode, show the companies that you can meet their minimum threshold of cognitive and executive capability for entry into their tech department... or don't work for them, it's that simple.