If you are using photoshop for image manipulation... GIMP is catching up.
But, if you are using photoshop to draw, Krita is a LOT better, and getting better.
Inkscape is still a bit clunky, but I am sure it will overtake InDesign.
But, when you use those big software packages for a living, it is really hard to transition out of them.
As far as I know, Inkscape is vector drawing app that takes on Illustrator.
InDesign does not have any competition. QuarkXpress is dead.
I never used Photoshop for drawing because it doesn't have a minimum of controls. It's a painting program, and not drawing. Still it's by a large margin ahead of GIMP in photo manipulation :(
For Krita I didn't even heard. I might check it on your recommendation.
Thank you.