I think good EVFs were available since about 2013. I compared the optical viewfinder of the Canon 5D with the electronic of the Olympus E-M1, and the EVF of the

I think good EVFs were available since about 2013. I compared the optical viewfinder of the Canon 5D with the electronic of the Olympus E-M1, and the EVF of the Olympus offered an equally large image, that also was brighter if the outside light wasn't very strong. The only complaint might be the limited resolution, but since then much higher resolution viewfinders have become available. And basically any optical viewfinder for smaller than 35mm formats is inferior, because the amount of light in the smaller format makes building of a large and bright optical viewfinder basically impossible The big advantage of EVFs is that it can do so much more than an optical viewfinder. You can enlarge it, display focus peaking, but most of all, you get a preview of the image you would take - especially previewing the exposure is very helpful. And of course, if you want to do video, the viewfinder of a SLR wouldn't be usable at all.