Its very useful and important, I have really good result for describe the image with the right words, like <Bloc’s App Non coding app easy to use with Bootstrap made in the UK> try to set those words of an image on your blocs homepage. And then it is crawled you will se the result, very effective. People are clicking and buying with there eyes.
The Alt-Tag is for Blind people, or people who has reduced sight, and they have an special software plug-in for there browsers, so the browser is reading up the alt tag for the image like, She was walking in the garden and she found an <image.jpg> Alt-Tag= a big green apple, and you know the rest.
I have one more wish, when I do the SEO in the Page Settings, I have to resize the window all the time, or going back and fourth with the Arrow key to get the text where I want it.
I would like to have an square with a cross, so I can freeze the window size.
I have done some suggestions in Affinity Photo, so you know what i talking about.