He doesn’t have to, he doesn’t even have to own the camera.
I am the target user for the R6 series and I use v30 SD cards because I can and because they’re enough for my needs.
Free will, you know?
It’s a wrong assumption to think that everyone is buying the fastest memory cards a camera can take. Not everyone is doing video, not everyone is shooting in bursts. The R6 has buffer for over a hundred photographs, and I’d be working the same way if it had half of that, as I’m not burst shooting.
I’d get pissed if they converted the R6 series to using two different memory cards, one being at 10 times the price.
I own several pairs of memory cards, that would increase the price of the camera to me by 10 to 20% right away, in order to keep working the same way. That’s just crazy for this price point.