Why do database entries have value? Well, usually because there are processes attached to them. Often it is as simple as having a court enforce the process.
I don't know why but the whole cryptocurrency space feels like a philosophical parody of the real world. Money without people. Contracts without enforcement. Ownership without property.
The common denominator between these being: process without purpose.
And this is why the parody works so well. The world is already like you describe, though it's hard to notice if you view it through the rose-tinted glasses that the ever-shrinking in-group is more than happy to sell to you for good "old" fiat money. (If 50 years ago is old.) Neoliberal "infinite growth" capitalism is already an inter-generational MLM, sanctioned by a global monopoly on violent enforcement. All power grows out of the barrel of a gun, and we have all become so delightfully non-violent... The logical conclusion: Oceania, Eurasia and Eastasia locked in perpetual war upon the background of a collapsed ecosystem?
Well, fuck that. Techno-capitalistic nation-states are an early-stage performance optimization. And since violent uprisings lead nowhere, we're doing the sane thing. We're refactoring 'em the fuck out of existence.
If "having a court enforce [a] process" is "simple", how come so many people already have "avoid courts", "distrust lawyers" as rules of thumb, and "don't side with authority" as a general life principle? For the marginalized majority, every state is a failed state, and every system is hostile and oppressive. The thing everyone's getting out of crypto is the same thing they've been getting out of all the other silly pyramid schemes, from Tupperware to contraband. Which is to say, the same things they've been aggressively denied by the state-sanctioned economic mainstream.
Hope. Opportunity. A voice.
A functioning parody of existing economical processes gives people the hope that there's a better economic system right around the corner. Maybe we just have to collectively sort of stumble into it.
Of course, it's only that simple if you have a simplified view of human creativity. But that's OK, too. Every invention that truly revolutionized our way of life was a somewhat accidental result of thousands upon thousands person-hours of organized research. And that's exactly what we're doing here - about as haphazardly as virtually any other kind of software development, but at the same time crowdfunded on a global scale.
Today, we're offering people the same sort of economic "junk food" that the current system has gotten them addicted to for the better part of the 20th century. Tomorrow, someone finally sneaks distributed consensus technology into the mainstream, and makes the world a little less corrupt.
It's beautiful.
Do I print a piece of paper? Do I show them a picture on my phone or something? Can't the previous owners of the NFT show the same picture? Can't anyone show the same picture on their own phone?
Or just have your phone broadcast the public keys via radio to a turnstile.