I know what you mean, but it's not really possible to manually denoise a picture the way the AI denoiser does. Let alone within 10 seconds. Plus, it's more of a niche usage. I don't think it consumes all that much energy.
Generating shitty images, creating deepfakes, prompting all kinds of bullshit... now that is a waste of energy as it really just makes the world worse. AI generated articles are popping up all over the internet. They aren't even reviewed anymore. Enshittification of the internet took some gigantic strides since the AI boom.
Good question, I'll look it up!