In history, large numbers of people have committed grievous mistakes under the notion of "It's popular so it must be the right thing." Axis powers during WWII, e.g.

"You can in fact fork Bitcoin today and attempt to create a market, will your new coin be valued as a Bitcoin and derive its current ~9000 USD price?"

Yes. They're called shit coins. I'll make 21,000,000 shit coins in my currency and sell you one for $9,000. You can, make your own shit coins and just sell one of your shit coins back to me for $9,000. Money need not exchange hands.

How about this? I will sell you an arbitrary magic number for $9000. It's value is only good inside those that trade these magic numbers. The only difference between my offer and bitcoin is that many people are trading these magic numbers.