My retort is usually a variation of one I've already posted in this thread: they do that to the same extent that taxis enable everyone to drive, which is something most people will intuitively understand as nonsense, even if they've given clear instructions to the driver and even though they've arrived at the intended destination. If you aren't driving, you aren't driving. If anything, the taxi service enables more people not to drive.
They're talking about the result, one must think. The idea that people who could not have approximate pictures of ideas that lived in their head can now have those things. They didn't create them by an in depth process, of course, and would be wrong to pass it off as though they did. But there is some value to the enjoyment gained from that existing (whether that relatively trival enjoyment is offset by other harms is for the reader to decide).
You're talking about the process and/or the developing of the skill of crafting and thinking about images better.
We also lack words to talk clearly about the distinction here around "make". Did I make a piece of art if I created a file on a computer in photoshop and then printed it? or did the printer make it? Did photoshop make it? (imo, all are true, but in differing senses of the word make). It seems to me that there is a sense that, no matter how trivial their involvement, a user of some AI art app is "making" something, in the same sense that steve jobs "made" the iPhone. In both cases, an engineer that literally designed the iPhone or an artist that spent years would perhaps rightfully feel upset by such characterization, but to get across the point cleanly is harder.
It's the same for the taxi. If I can't drive (perhaps I never learned, or some flaw with my body doesn't let me), a taxi does enable some things I could never do before. I am, of course, not literally the one driving. But if I can get to the shop myself now, there is something there.