That sucks. Touchscreens have become so cheap (because economies of scale), Audi is probably saving manufacturing cost by not having physical buttons, simply because of the custom design cost of integrating buttons into a PCB and then programming it[1]. Touchscreens might even be cheaper than non-touch screens. They often have higher resolution. Audi is probably transitioning to using software stacks designed to build touch-screen apps instead of buttons and don't want their software devs to even think in that outdated mode of "buttons". It's completely self-serving and chasing the design trends, tripping after Tesla tech woo, not consumer demand.

[1] Which is totally ridiculous IMHO, because even with my completely amateur skills, wiring up a few buttons to an embedded chip is NBD.

I doubt design cost is relevant, and software stacks also don't really care. Support for hardware buttons is a very thin layer, and widespread.

I only drove an Audi once, and loved that little joystick thing. It was perfect.