A few examples.
Sketch’s color picker is horrible. One color model? It’s the size of a match and I can’t make it bigger? No complementary colors? It appears in a floating panel that runs off the bottom of the screen and you can’t reposition or pin it? HSB is the only color model I use to adjust colors and it’s not well supported in Sketch, I can’t easily adjust the brightness or saturation of a color. An RGB slider is useless. Illustrator has a vastly superior color palette.
No shared color palettes? What, so, each designer is supposed to manually enter in all the brand standard colors into each new document on their own? No spot colors allowing me to update a color everywhere it is used? Sucks.
No text styles? No paragraph styles? So, I guess if I want to change a text style I have to manually hunt for all the places it’s used?
Drawing sucks. So wait, I can’t just grab a curve and adjust it? I have to mess with bezier handles? Can’t draw a selection around multiple nodes? No path filters?
What help does Sketch give you with HTML/CSS that Illustrator doesn’t? I’m unaware.
Development teams do not use the source files that I create. I give them the PNGS. We use style guides with standardized sizes and spacing so they aren’t taking dimensions from a file. I don’t even try to make my design files have the pixel perfect spacing because that will be taken care of automagically by the style guide. In any case, development teams frequently do not use Macs so they wouldn’t be able to use a Sketch file anyway.
The article about the difference between Sketch 2 & 3 isn’t super informative. Contextual menus are not exactly cutting edge tech.
I will say I do like how Sketch as made the layers pallet central to it’s UX. Illustrator seems to pretend you don’t really need the layers palette.