I think this is crap, to be honest. There are plenty of high end designers (eg esther perbandt, who works almost exclusively in black, Christian Siriano who does a lot of all black looks) who do absolutely amazing looks in all black. They’re fashion but also wearable.
I’m not going to bother watching the video because I think it’s an affiliate link that’s just monetizing clicks, but a very surface level of exposure to fashion designers over the last decade show that the over enthusiastic, all caps headline is just wrong.
Color is great, color is fun. A lot of my wardrobe is insane with colors. But to make a blanket statement like that just seems naive. All black is a statement look, just like wild colors and patterns are. It just comes down to a look that suits you and fits what you’re trying to put out there.