But there still are people making art with older techniques. There is a greater variety of art being made today than ever before in history. The development of new techniques has made art richer rather than poorer. Yes, the most commercially focused art chooses techniques based on price (far cheaper for a single person to stack synths than to pay a full orchestra) but that's okay.
Hip hop and electronic music have been creating totally new things for decades without ever touching a physical instrument. Music didn't die, it flourished.