The way to undo things in photoshop is indeed absolutely frustrating. I want multiple undos, and a separate command for toggling between states,
Most of the time I don't want to "compare" what I did, I just simply want to go back to a blank state where I can try again if I didn't like my input, say I'm trying to shade a square and give it some shadow, i make 5 strokes, what happens for me now is is that I can only undo a single input and then it toggles between that one undo and my last input. But if I use back a step and go back to a state I like, and make a new input, it doesn't overwrite what I previously did and don't want, in fact it just keeps every state so that the more i input and back a step to find the blank state without my errors, the more I have to press back a step, so that means the more mistakes I make the more times I have to press the button, and It didn't used to always do this either, I remember it used to overwrite history states that were ahead of the one you had selected if you made a new input. Now it just saves them all, and its madness.
Most of the time I don't want to "compare" what I did, I just simply want to go back to a blank state where I can try again if I didn't like my input, say I'm trying to shade a square and give it some shadow, i make 5 strokes, what happens for me now is is that I can only undo a single input and then it toggles between that one undo and my last input. But if I use back a step and go back to a state I like, and make a new input, it doesn't overwrite what I previously did and don't want, in fact it just keeps every state so that the more i input and back a step to find the blank state without my errors, the more I have to press back a step, so that means the more mistakes I make the more times I have to press the button, and It didn't used to always do this either, I remember it used to overwrite history states that were ahead of the one you had selected if you made a new input. Now it just saves them all, and its madness.