The TL;DR is that high contrast between background and text colors is important, and that for many users, black text on a white background is a) most legible and b) most professional-appearing.

Learn how to set the background color for selected text (instead of the entire document) in TextEdit ...

The Windows Photos app is getting background blur, and Snipping Tool will copy text from your PC or Android screenshots. The Windows Photos app is getting background blur, and Snipping Tool will ...