Neil V makes some good points as usual, but he's also being very misleading in that video.
He's comparing his Black Foamie Thing, bounced off a conveniently nearby wall, to other accessories designed to be used in more common environments that don't have his high studio ceiling - 14ft he says, or 4.3m. That's extremely high, almost double the standard domestic ceiling height of 2.3m. Therefore, with accessories designed for lower ceilings the bounced component is going to be very weak - like 2 or 3 stops down on where it should be. Huge difference. So of course he got poor results. In other words, I'm sorry to say that he's deliberately making them look bad. In the much more typical domestic kind of environment they were designed for, most of them would give very good results.
He also says to just bounce off a wall/ceiling behind, and that is certainly a very effective method in the right circumstances. But you don't always have a nice white wall just the right distance behind, and even when you do, he doesn't mention the big loss of brightness that bouncing from behind suffers. For that technique to work, you need a powerful gun, to shoot at low f/numbers, and/or ramp up the ISO. Solos and couples are okay, but larger groups at f/8 not nearly so easy. The other thing is when you start bouncing off walls and other furnishings etc, the light picks up a colour cast that may or may not be acceptable.
There is a reason why most flash accessories work the way they do, sending most of the light up for soft ceiling bounce, plus a dash of direct-light fill-in to lift shadows under eyes and noses and chins, and put a sparkle in the eyes (basically like a bounce card). In other words, the bounced light should be dominant, not the fill-in, and he's showing it the other way around.
I have a bag full of these bits and pieces, including the Black Foamie Thing, but my go-to accessory is usually the Lumiquest QuikBounce, because it works well, quickly and easily, in most situations (even outdoors). It's also relatively efficient, doesn't waste precious light, and that translates into faster recycle times that are important in social situations with fleeting expressions. It's a rare treat to be able to get out the Black Foamie Thing, or to bounce from behind.