Unless you’re already using a laptop that has a QMK keyboard and have mapped the fn + WASD keys to something else, you aren’t losing keys. You’re gaining QMK.
I find it ideal to be able to keep my left hand on the keys and my right hand on the mouse/trackpad as much as possible. Also, if you play games, moving around on a computer with WASD is pretty natural.
I agree that having full-size arrow keys would have been better than not having them, provided it doesn’t ruin the Shift key like that layout does on some keyboards.