As far as Images search is concerned, you will lose only an insignificant number of visitors (since the bulk of Google Image users have everything they need on the google result page and do not visit the source site); however, you considerably reduce the fraudulent copies of your pictures (because Images at Google are shown without the related copyright terms and they are then copied extensively). So, all together, the change is positive.
No, the change would be catastrophic, not "positive," if I hid my pages from Google. The last 3 months (per my Google Search Console) I received 95,000 clicks on the webpages and 22 clicks on images. Images are meaningless in this discussion. And lest we forget, the original poster was speaking about should she "protect their content from Google ... [if] my content were not found on Google" [quote from the original post]. If I could protect my content from Google so that they could not find it, I would have lost 95,000 clicks the last 3 months on my webpages. This would be suicide to a website. Please answer this: if you somehow exclude Google from your website, where do you plan to get your traffic?
You already mentioned your organic traffic numbers. My question to you was, how high your click through rates are, compared to the last 5 years with the same visibility. How did you do it before Google existed?
Irrelevant. Google was already operating for 6 years before I started my website 15 years ago. I'll just respectfully check out of this thread. We are seeing things quite differently, so let's each just go our ways with mutual respect.