This really depends on what you mean by "touch screen" and "image editing" as well as your own workflow and efficiency.

I've been a Photoshop user for more than 20 years. I could use a Cintiq or other touch screen option IN ADDITION to a desktop/laptop to see directly on the drawing surface what I'm working on.

However, the many 2-in-1 options are very poorly designed for professional usage. Lenovo and Microsoft for example lose all access to keyboards when in drawing tablet mode. To make matters worse unlike Cintiq which offers buttons on the side at least neither Lenovo or Microsoft has any so you can't even setup a few hotkeys. There's nothing! Zooming in and out, undo, switching tools, all of it has to be by pressing menu or panel options.

Now if you're only using Lightroom than this isn't as big of an issue. You'll be a little slower on say flagging and rating but the rest isn't too bad. If you're doing work in something like Photoshop or Affinity Photo though forget it.

Stick to Cintiq or just an Intuous Pro connected to a more traditional desktop or laptop. You might also look at Wacom's ExpressKey Remote but even that for me is limited when I know and use hundreds of shortcuts.

I would encourage you to find the nearest Microsoft store to you and try out a Surface or Lenovo. The one by me at least had a few loaded with Adobe CC so shoppers could try it. For your every day shopper that has no idea what they're doing its a fun gimmick in a shop getting to play in Photoshop right on the screen. But for a Professional Workflow the efficiency just isn't there without key strokes.

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Update if you mean a touch screen that isn't a tablet. That's also a gimmick that would find use for maybe Lightroom and not much else. The entire point for editing work of a touch display is having pressure sensitivity for masking, airbrushing, painting, etc. You'll be much better off using an Intuous Pro connected to a non-touch laptop/desktop if that's what you're referring to.

So really my answer is the same for touch screens as it is for 2 in 1s but for different reasons. Touch Screen lacks precision and sensitivity, 2 in 1's lack keyboard while in tablet mode.