If you had even 10% of Elon's money, you (well, I) WOULD spend a fortune on audio gear if you love it. Why wouldn't you? Even if you were "only" worth $100 million, you could spend 2% of your net worth (even 1%) on a room and a system that would be nirvana...bliss. You say you wouldn't, but that would make you an aberration if you won the $100-500 million lotto. One's perspective changes with that kind of money, I believe.
Of course, maybe you'd choose to buy a yacht or private jet, and that will make a world-class hi-fi seem absolutely cheap in comparison! You don't need to hire a pilot or skipper to run your stereo for you. It won't cost you $10% of the cost of your stereo system just to crew, maintain, insure, and staff a stereo like it will a yacht. If your yacht is worth a mere $50 million, it will cost you $2-5 million a year just to maintain it before you ever leave the dock!
I always keep a short list of "lotto dream" hi-fi systems in my head. At my age, I don't dream of gorgeous nubile women anymore. One of those would just give me a heart attack or stroke, or my wife would kill me. 😂
It’s really more about would I want to buy... say ...$40k speakers, even if they sounded like heaven. I would not. Again no judgement on those who do... enjoy the sound!