This is the foundation of the new WordPress editor. Take atomic pieces, and combine them to make whole sections and layouts. Best yet, no fumbling with floats if you want to put some text next to an image!
A nice example of what Gutenberg can do. I am not using it here, the old editor suits me and supports all of the IndieWeb plugins. It will answer some of the requests we have on Glow Blogs when it arrive there.