You’ve got the motive back to front.
yah, let’s get rid of these cheap, easily manufactured and implemented dials and knobs
In modern cars those buttons are an input to a body computer which then sends commands over the vehicle data bus to another module that performs the appropriate function. The touchscreen option is much cheaper once you have more than a few buttons to deal with.
Buttons have different physical shapes, the little decal for the button on each one has to be printed and put on top, each one needs to be connected to power, each one needs to be slotted into the dash somewhere , each one needs to be backlit so you can use it at night, and the signal for each one has to be routed somewhere through increasingly bulky harnesses, etc etc.
A touchscreen sits on the vehicle data bus and with a bit of software, sends whatever command is needed.
Is it a great user experience to press fiddly buttons on a touchscreen while driving down a bumpy road? Fuck no. But it is definitely cheaper and less complicated for the manufacturer.
Does it download the actual music tracks from youtube-music, or does YouTube helpfully provide the video version of the music?
I’ve used a few downloaders and it seems these days that every music video is a whole “production” with 30 seconds of dialogue and intro before the actual music starts, or there’s background noise over the first dozen bars (because the artist is in a cafe or car park or on the train in the clip) and all of that is just a bit tedious when listening to the audio only.