Lose all the circa 1980s modal dialogue box stuff
Interesting you don't have a Category for "Usability"!
If i want to change background colours for a group of cells I have to click 3 times all at different places on the screen to bring up the macOS colour picker, the only place I can store my own custom colours, just to do it. Where as in Numbers I can just click the floating colour palate if I have the Cells sidebar up (I prefered Numbers and all the iWork apps when almost everything was floating palettes than side bars which although not modal means more clicking)
This is just one example, there are hundreds of others where there is just too much modal dialogue box clicking to do a simple thing that must be repeated over and over.
It's 2017 Microsoft, come on, life the GUI into this century!