You can try it on an iPad with Magic Keyboard attached, it's very good to be able to do precision through the trackpad and then casually move large things on the screen with your fingers.
Trackpad is nice for a device you can lay flat on a table or keep on one hand while sitting on the sofa, not too much when the device has a keyboard permanently attached to it and it cannot fold. I know I have a thinkpad like that and I never use the touchscreen.
Two keys rather than one, but makes up for it by not being way off in some oddball part of the keyboard. You can one-hand it pretty easily, since there's an "option" right next to the arrow keys.
However, like on Windows, I suspect macOS would increase the tap target size on lots of the touchable elements. Even if I don't use the touchscreen, I would still have to pay the touch target real estate tax in my applications.