Editing images (textures) in external editors in real time

Why do I so rarely see in the programs the possibility “directly” (I think this is done through RAM) to edit textures in any drawing program (if only I support converting to the correct format for the 3D program, be it png , dds, any other)?

Because internally, just about every application handles image data differently enough that you can’t just work on a RAM dump directly.

Well, this is a comprehensive answer. It’s a pity. I hope sometime (in 50 years) programmers will agree on certain standards.