I used left touchpad as a touch menu when I was using the left joystick. After moving to the left touchpad I prefer it over joystick due to being able to rely on a sprint hold mapping it on the outer edge without accidentally triggering it like I would on the joystick. And I've come to love mapping stuff like crouch, slide, or dash to it too so combining movement actions to touchpad clicks. Frees me to use back buttons for other stuff and further reduce my need to lift my thumbs away from movement and camera controls.

That's my experience as left joystick and left touchpad user.