Yes, any analog input is going to be rare in the future. But if kjmann14's device provides good image quality in a single device rather than a clunky chain of cables, and is even optimised particularly for the Amiga, I'm sure it's a nice option.
I use a Startech card to capture RGB. It's only about €100 or so.
[ Show youtube player ] captured with it. Original is 50fps of course but YouTube does not allow that yet.