I'm pretty sure it's still working and still helpful. Google claims they want it to be descriptive of the image but really, how could they possibly tell? Also, this allows for the image to show up in google image search which can be helpful (in all cases but fluctuates depending on the niche). If you're in a niche where people want to see images, it would be helpful to add them. I don't have good examples sorry but yeah, Kvchosting pretty much covered the rest of it: hover tool tip, keyword on the page, add it in the img tag.