[TonyStr]

No, this is wrong.

> When we pack high-density information into a data table or a complex dashboard we are increasing the visual entropy of the entire system. Forcing the brain to decode intricate, non-universal shapes in a tiny 16-pixel footprint, creates a “cognitive tax” that users pay en masse every time they scan the table.

This is not how the brain processes icons. Icons have their meanings embedded through related patterns. If you rely on common icons such as x, checkmark, plus, shopping cart, arrows, three dots, etc. the user already associates certain meaning/behaviors with these icons (and will be surprised if they act differently in your application). Introducing new icons is more challenging, because you have to convey their meaning to the user. At no point does the user have to stare at an icon and try to "parse" it pixel-by-pixel.

In all of OP's provided examples, the icons are supported by both labels and colors, which removes all ambiguity. You can argue that the icons are pointless in this case, but they certainly do not increase any cognitive load. Is it harder to identify a tiger than a lion, because his fur is covered in stripes?