procreate has a feature that lets you make your lines straighter, and your drawings into perfect shapes!
I love Procreate and all but I hope all these requests to improve drawing features in Illustrator for iPad don't take away from it's core in the end. Ai has never really been a "drawing" application to begin with. Straight lines and perfect shapes though have been home field to Ai for decades using pen, rectangles, ellipses and pathfinder. I absolutely love that Adobe put emphasis into getting these to the ipad version.
This is so important. Its not even a feature, its the basic mechanism to make structured art, which is one of the most common uses in illustrator in the first place!
Dalton Pearson commented
You could be able to do these tasks with the pen tool while using the touch shortcut as well as the pathfinder panel.