What cursor keys? There weren't any cursor keys on an iPhone. It's a touch screen device. The few punctuation keys are gone. They are on the number screen.
In landscape there used to be two left-right cursor keys on the right side of the keypad along with most-used punctuation without having to go to the number screen. I know it’s a personal nitpickey thing but it was nice as I use the phone or tablet almost exclusively anymore.
See tip #7: http://www.gltrends.ng/2016/10/9-cool-iphone-keyboard-tricks-know/