Autodesk SketchBook might be a bit more popular than Karbon. We know about 1 link to it since March 2021 and only 1 link to Karbon. We are tracking product recommendations and mentions on various public social media platforms and blogs. They can help you identify which product is more popular and what people think of it.
Similarly, Karbon (part of the Calligra suite) absorbed the suite's dedicated flowchart tool, and is pretty functional for this purpose, but it's primarily developed for Linux. While they have Windows installers, they're not the easiest to find and aren't directly supported. Source: about 2 years ago
Try sketchbook.com, the official site. I don't know if it's different from the Microsoft store version, but it might be. There should be a free trial. Source: over 2 years ago
Inkscape - Inkscape is a free, open source professional vector graphics editor for Windows, Mac OS X and Linux.
Krita - Krita is a professional FREE and open source painting program. It is made by artists that want to seaffordable art tools for everyone. Concept art. texture and matte painters, illustrations and comics.
Sketch - Professional digital design for Mac.
Procreate - Procreate is the most powerful and intuitive digital illustration App available for iPad®.
Vector Magic - Easily convert JPG, PNG, BMP, GIF bitmap images to SVG, EPS, PDF, AI, DXF vector images with real full-color tracing, online or using the desktop app!
Clip Studio Paint - The artist's software for drawing and painting.