Serif Software is developing a new vector drawing application called Affinity Designer. It's currently in beta testing and you can try it out for free:
https://affinity.serif.com/
It's lacking a lot of features that a technical illustrator might need... there's no way to draw a grid, create guides, skew/distort artwork, snapping isn't very robust.
That said, it's still young and being actively developed. Drawing and effects feel quick and the interface is very nice. You can set up to 8192 steps of Undo, it has built-in AutoSave, and you can zoom to freaking infinity — because why not, it's vector. Where is this stuff in Illustrator??? You can also sort of work back-and-forth between vector drawing and raster painting, but I've only started playing with that.
The attached screenshot is demo art provided with the software (not my work).
I'm interested to see where this project goes.