That money absolutely has tangible value. If Jeff Bezos is willing to pay $500 million for a yacht, but I'm willing to pay $600 million to build schools, the market should favor building the schools and society ends up with a bunch of schools rather than a single super yacht.
That's why we need some kind of significant wealth tax. Take the money away from people that will choose to allocate resources to yacht building and other frivolous things and spend it on stuff that has an obvious benefit to society.
Inflation may be a bitch, but last I checked I could walk into McDonald's with a green piece of paper with a "$5" printed on it and walk out with a Big Mac, no questions asked.
That's only because the super rich are dictating what's in demand. If you take all the money being spent on luxury watches and start spending it on dental care for children, the market should reduce the supply of watch makers and increase the supply of dentists in order to meet the demand for each.
I wonder how much of our problems arise because our intuitions and assumptions on the small scale simply fail on the macro scale