This is an old idea that has floated around for a while. I have not seen it on RCS yet.

Blender already has most of the features of a standard image editor such as Photoshop/Gimp. I see no reason to not make it 'official' with a dedicated/optimized workspace. This isn't a vendetta against Ps or anything, just that it seems like low hanging fruit that could easily expand the user base of Blender.

IE Features Blender Already Has:

• Vector shapes / paths:
  • Boolean modifiers for meshes / shapes
  • Strokes ( some niche features missing )
• Masks ( raster/vector )
• Pattern generators ( Clouds, voroni, etc )
• Painting / Brushes
• Image color modifiers ( all the various ramps in the node editor )
• Image distortion:
  • Blur — There's an add on for this (afaik) and could/should be internal anyways.
  • Warping — Better to use meshes for this anyways (more non-destructive and capable; see Puppet Warp in Ps).

Indirectly Has:

• Classic layer + grouping system => Collections is practically equivalent.
• Clipping Masks => Boolean modifier can kind of do this, but collections can't have modifiers atm.
• Symbols / Smart Objects => Linked Copies is basically equivalent.

Missing:

• In Photoshop, groups can have styles and be clipped by layers (and masks obv). Collections don't support modifiers atm, and I'm not sure how clipping would work here. This powerful capability would need to be replicated somehow.
• Planes can have masks and effects can build off the masked shape, but I doubt the edge handling w/ effects (such as bevel) is as good as traditional 2D editors.

Vision:

• A new 'Image Editor' workspace with a UI similar to established 2D image editors. Most of the widgets for such a workspace already exist:
  • Canvas => Orthograpic view of scene. ( perspective view should be a layer-based option imo. )
  • Layers => Collections widget; layers would generally be planes but can be any mesh really.
  • Brushes => Brush widget
  • Colors => Color Picker w/ Color Palette.

I'm sure I've belabored the point — I just feel that if the Blender team is okay with Sequence Editor and Grease Pencil extending Blender's functional identity (what kind of software it is), I don't see why Image Editing can't be another extension.