If I had to make a wild guess as to why it’s designed that way? Cleaning flat buttons seems way easier than cleaning knobs. And no moving parts. Maybe more resilient (can be made with cheaper parts) considering the flimsy electronics that would be underneath the knobs compared to the more industrial (robust?) kind under an electric range.
My wife and I drive almost the same model of Audi, separated by a couple of years. One still has physical buttons for infotainment and one has a touch screen, but both support Android Auto and CarPlay.
I prefer the physical controls for it, because I can glance at the screen and know “turn right two clicks and press down” to get where I want, and then look back at the road while I do it.