It obviously depends wildly on the material used, and the method of construction. Simply routing the edges as done in the video has little effect, but I cut my rings with a plasma torch ( 15k degrees Celsius give or take ). That leaves a hardened edge, which is the critical area, and which is beneficial in this application. With the router method from the video, there is a conflict between choosing a hard material and being able to machine it. Your garden variety router may struggle with some harder materials, and/or you will have to feed very slowly.

I have not run any of mine long enough to know the actual lifespan, but after ~2k miles, I can barely measure any wear, so I'm not concerned that they will die young. I cannot measure any wear-rate difference between the aluminum and stainless steel rings that I've produced. That said, I tend to keep my drive trains clean and well-lubricated, and don't experience as much wear as many people do, even with commercially-produced sprockets and chains. So YMMV, literally.

As an aside, I quoted a price for 1/8" 7075-T6 a couple comments ago. FYI, in case anyone is pursuing this, 1/8" is too thick, the quote was just to give an idea on a source. You actually want 12ga ( .0808 ) for at least anything <13 speeds. Not sure about 13s.