> In the end what happens is people use text overlays in the IMAGES in order to reply to each other.
That doesn't sound optimum use of image at all.
> Or you can make the message memorable.
And use image that make it even more memorable at the same time.
Text and images are tools, both can be misused, but that doesn't means that they are bad. Remember SMS text? Works for sure, clearly not optimal, yet text is pretty good to make message memorable.
I can explain in a thousand word an issue on a page, but you can also just share a screenshot. That's an optimum use of images. Sure you could just write "see screenshot #1", "see screenshot #2", etc.. but I'm pretty sure you'll agree that it's not optimum.