Btw what is current MacPaint successor? Is there any? Do I understand correctly it used to be shipped with the Mac?
Preview is great to some extent and does a lot of useful things for me but it's designed to modify existing images, and I'm still missing a software to draw a square, circle, some text etc.
Try Paintbrush (open-source MacPaint-inspired app), Pixelmator Pro (more advanced), Acorn, or even Apple's built-in Preview has basic drawing tools under the markup icon when viewing images.
Preview is great to some extent and does a lot of useful things for me but it's designed to modify existing images, and I'm still missing a software to draw a square, circle, some text etc.