What are some alternatives?
When comparing Illustrio and Affinity Designer, you can also consider the following products
Evie by unDraw - MIT licensed illustrations for your next project
Sketch - Professional digital design for Mac.
DrawKit - MIT licensed SVG illustrations, in 2 styles
Inkscape - Inkscape is a free, open source professional vector graphics editor for Windows, Mac OS X and Linux.
Flaticon - A database of free vector icons.
Adobe Photoshop - Adobe Photoshop is a webtop application for editing images and photos online.