There are many reasons to do this
How to Completely Disable Your Laptop Keyboard in Windows 10 2020!
There are many reasons why you might want to disable a laptop keyboard.
You may want to prevent others from accidentally pressing keys on your laptop and potentially causing data loss or corruption. You may also want to disable the keyboard when cleaning your laptop to remove any accumulated dust or dirt.
Your laptop keyboard can also get damaged by spilling or breaking. In that case, you may need to use another keyboard instead of your laptop keyboard.