Are there any good flash diffusers besides DIY paper?

I've built a homemade paper flash diffuser:

Flash diffuser 1

Flash diffuser 2

It broadcasts the flash while directing a large amount of it in the direction of the subject. Of course, ceiling lighting wastes a bit of flash power (the paper transmits a little light), but at least there is some directionality.

It gives excellent results (left, with diffuser, right, direct flash):

With and without diffuser

My question is: are there similar broadcasters available on the market? Of course, I do not mean an exact replica built from paper, but rather a more durable diffuser that achieves the same functionality and is a little directional like my DIY diffuser.

By broadcaster, I mean something that can be used with the camera and something that is so light that it is possible to carry it with the camera. Of course, with an external flash, you can use umbrellas, but they are too big to carry.

Why do we use patterned glasses and flash diffusers?

I first noticed it on the xenon flash on my Nokia N8. Seen from an angle, one could easily see the glass on the front of the flash tube which had clearly defined vertical sections that gave the glass the impression of being stuck with different pieces of glass.

Then I saw objects called flash diffusers for claw xenon flashes.

So why do flashes have diagonal cut patterns on their glasses and what are these flash diffusers? How would it happen if these patterned glasses and flash diffusers did not exist?