What are some alternatives?
When comparing Retrowave Illustration Pack and Stubborn Illustrations, you can also consider the following products
Stories by Freepik - Awesome illustrations for your next project
Evie by unDraw - MIT licensed illustrations for your next project
Illustration Tools - Directory of tools and resources for illustrators
DrawKit - MIT licensed SVG illustrations, in 2 styles
Glaze - Turn your photos into printings with your unique styles.
Humaaans - Mix-&-match illustrations of humans with a design library.