As far as millennial's preferring experiences, I would argue that a nice music/theater system IS an experience (or at least creates one as you say), and one that someone can revisit each and every time they use it. It also need not be a huge financial outlay to get something of reasonable quality today. But one has to experience and recognize the better quality, and the value of it, in order to be interested in recreating that experience for themselves. And that is not limited to millennials.
I purchased my first home theater system around 20 years ago. I wanted something of quality and spent what seemed at the time to be a small fortune for a 5.1 system (even though it was probably considered to be mid-fi and not even close to what many were paying for their systems). We still have most of that system today and my wife, who has little interest in such things, has mentioned to me any number of times that, although she felt it was expensive at the time, in retrospect she believes it was money very well spent as we have enjoyed the benefits of that system for many years.